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Volume 5580 26th International Congress on High-Speed Photography and Photonics

Dennis L. Paisley, Stuart Kleinfelder, Donald R. Snyder, Brian J. Thompson March 2005

Conference Location: Alexandria, VA, USA Conference Date: Monday 20 September 2004

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Keynote Paper

Select this Article		A summary of the Space Shuttle Columbia tragedy and the use of digital high-speed photography in the accident investigation and NASA's return-to-flight effort J. Michael Pereira, Matthew E. Melis, and Duane M. Revilock Proc. SPIE 5580, 1 (2005); http://dx.doi.org/10.1117/12.579291 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract On February 1, 2003, the Space Shuttle Columbia broke apart during reentry resulting in loss of seven crewmembers and craft. For the next several months an extensive investigation of the accident ensued involving a nationwide team of experts from NASA, industry, and academia, spanning dozens of technical disciplines. The Columbia Accident Investigation Board (CAIB), a group of experts assembled to conduct an investigation independent of NASA concluded in August, 2003 that the cause of the loss of Columbia and its crew was a breach in the left wing leading edge Reinforced Carbon-Carbon (RCC) thermal protection system initiated by the impact of thermal insulating foam that had separated from the orbiters external fuel tank 81 seconds into that mission's launch. During reentry, this breach allowed superheated air to penetrate behind the leading edge and erode the aluminum structure of the left wing which ultimately led to the breakup of the orbiter.Supporting the findings of the CAIB, were numerous ballistic impact testing programs conducted to investigate and quantify the physics of External Tank Foam impact on the RCC wing leading edge material. These tests ranged from fundamental material characterization tests to full-scale Orbiter Wing Leading Edge tests. Following the accident investigation, NASA turned its focus to returning the Shuttle safely to flight. Supporting this effort are many test programs to evaluate impact threats from various debris sources during ascent that must be completed for certifying the Shuttle system safe for flight. Digital high-speed cameras were used extensively to document these tests as significant advances in recent years have nearly eliminated the use of film in many areas of testing. Researchers at the NASA Glenn Ballistic Impact Laboratory have participated in several of the impact test programs supporting the Accident Investigation and Return-to-Flight efforts.This paper summarizes the Columbia Accident and the nearly seven month long investigation that followed. Highlights of the NASA Glenn contributions to the impact testing are presented with emphasis on the use of high speed digital photography to document theses tests.

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Novel Cameras and Sensor Systems

Select this Article		Ultrashort-pulse EUV and soft x-ray sources based on high-harmonic generation: principles and applications Ra'anan Tobey, Daisy Raymondson, Emily A. Gibson, Chi-Fong Lei, Ariel Paul, Sterling Backus, Mark Siemens, Xiaoshi Zhang, Margaret M. Murnane, and Henry C. Kapteyn Proc. SPIE 5580, 12 (2005); http://dx.doi.org/10.1117/12.579521 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract High harmonic generation (HHG) is a useful source of coherent light in the extreme ultraviolet (EUV) region of the spectrum. However, both the conversion efficiency and the highest achievable photon energy have in the past been limited in the past by the inability to phase-match the frequency conversion process. In this paper, we summarize recent results on the development of new techniques for phase-matching the high-harmonic conversion process. We also summarize finding from three series of experiments that make use of the coherent EUV light generated using HHG: 1) probing of acoustic dynamics in materials; 2) monitoring of chemical dynamics at surfaces using photoelectron spectroscopy; and 3) time-resolved plasma imaging.

Select this Article		A high-speed four-wavelength infrared pyrometer for low-temperature shock physics experiments A. Seifter, K. Boboridis, J. R. Payton, and A. W. Obst Proc. SPIE 5580, 18 (2005); http://dx.doi.org/10.1117/12.571456 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In addition to the standard problems associated with contactless temperature measurements, pyrometry in shock physics experiments has many additional concerns. These include background temperatures which are often higher than the substrate temperature, non-uniform sample temperature due to hotspots and ejecta, fast sample motion up to several km.s-1, fast-changing sample emissivity at shock breakout, and very short measurement times. We have designed a four channel, high speed near-infrared (NIR) pyrometer for measurements in the 400 to 1000K blackbody temperature range. The front end optics are specific to each experiment, utilizing preferably reflective optics in order to mitigate spectral dispersion. Next-generation instruments under development are also discussed.

Select this Article		Ultrafast three-dimensional microscopy of laser photothermal imaging materials Hyunung Yu, F. Richard Kearney, and Dana D. Dlott Proc. SPIE 5580, 24 (2005); http://dx.doi.org/10.1117/12.586018 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Time-resolved microscopy in a variety of configurations is used for three-dimensional imaging of laser photothermal materials used in offset lithographic computer-to-plate printing applications. Materials having an ink-repelling silicone layer and either a metallic absorbing layer or an energetic absorbing layer are studied. The energetic layers result in lower exposure thresholds when 10 microsecond and 2 microsecond duration near-IR laser pulses are used. The images explain the mechanism of threshold lowering, as a result of hot gas from the energetic layer causing the silicone layer to balloon. The expanding balloon results in less laser energy needed to produce an exposed spot.

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Detonics, Ballistics, and Dynamic Materials Response

Select this Article		Observations on the impact of a spherical projectile on particulate aggregations Masahiro Nishida, Koichi Tanaka, and Yukinori Matsumoto Proc. SPIE 5580, 34 (2005); http://dx.doi.org/10.1117/12.567218 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The dynamic behavior of particulate aggregation subjected to the impact of a steel spherical projectile was simultaneously recorded using two high-speed video cameras at different angles and analyzed numerically using a discrete element method. The effects of the impact velocity (1-25 m/s), impact angle (0-65 degrees), and size of the steel projectile on the dynamic response of particulate aggregation and projectile were examined. The movement of the projectile after impact can be classified into four types: penetration into particulate aggregation; stopping at the particulate aggregation surface; rebounding from particulate aggregation; and horizontal movement along the particulate aggregation surface. The type of movement depended on impact velocity and impact angle. The defining boundaries between the four types of movements became clearer as the size of the projectile increased. The results of numerical simulation also indicated that the magnitude, direction, and bifurcation of contact forces propagating into particulate aggregation play an important role in the change of the projectile's movement after impact.

Select this Article		Impact-induced collapse of aluminum honeycombs with cell defects Koichi Tanaka, Masahiro Nishida, and Souhei Takamiya Proc. SPIE 5580, 42 (2005); http://dx.doi.org/10.1117/12.567040 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Dynamical deformation and collapse process and stress wave mechanism of an aluminum honeycomb with a defective cell subjected to the in-plane impact of a rigid impactor were investigated experimentally. Deformation process was visualized using a high-speed video camera and a CCD camera and wave propagation mechanisms were investigated using a force gauge at the fixed end and strain-gauges glued on the cell walls. Also, numerical simulation was made using a shock code, AUTODYN-2D. The defect introduced in cells greatly affects wave propagation mechanisms and cell deformation process. The present results were compared with our previous results.

Select this Article		Special tasks on FXR in detonics Manfred Held Proc. SPIE 5580, 51 (2005); http://dx.doi.org/10.1117/12.570255 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Flash X-ray (FXR) is a well known diagnostic technique for many applications. But special tasks give new requirements on the arrangements. Two examples to this are presented here. One task was to measure the asymmetric fragment velocity distribution in the radial directions of "Velocity Enhanced Warheads". This was possible with one flash X-ray, where the X-ray tube was arranged along the charge axis. To find out, what the the true dagonal distances are, the impacts of the radially dispersed fragments on witness plates were used. With the help of the in this way so defined elevation angles the velocities could be well calculated by the displacement distances on the x-ray films. The special test arrangement with the analysis procedure will be presented.Another task was to measure the momentum distribution of anti-tak mines, lying on the ground or levelled to the ground or 100 mm buried with the help of a double flash X-ray equipment. The transferred momenta could be very well measured. These data are important calibration inputs for numerical models of these very fast events. Test set-ups with achieved results will be presented, too.

Select this Article		Full-scale high-speed schlieren imaging of explosions and gunshots Gary S. Settles, Torben P. Grumstrup, Lori J. Dodson, J. D. Miller, and Joseph A. Gatto Proc. SPIE 5580, 60 (2005); http://dx.doi.org/10.1117/12.580997 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract High-speed imaging and cinematography are important in research on explosions, firearms, and homeland security. Much can be learned from imaging the motion of shock waves generated by such explosive events. However, the required optical equipment is generally not available for such research due to the small aperture and delicacy of the optics and the expense and expertise required to implement high-speed optical methods. For example, previous aircraft hardening experiments involving explosions aboard full-scale aircraft lacked optical shock imaging, even though such imaging is the principal tool of explosion and shock wave research. Here, experiments are reported using the Penn State Full-Scale Schlieren System, a lens-and-grid-type optical system with a very large field-of-view. High-speed images are captured by photography using an electronic flash and by a new high-speed digital video camera. These experiments cover a field-of-view of 2x3 m at frame rates up to 30 kHz. Our previous high-speed schlieren cinematography experiments on aircraft hardening used a traditional drum camera and photographic film. A stark contrast in utility is found between that technology and the all-digital high-speed videography featured in this paper.

Select this Article		Experimental validation of advanced explosive/metal interactions David E. Lambert Proc. SPIE 5580, 69 (2005); http://dx.doi.org/10.1117/12.582872 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The extremely high power density stored in explosives drives their selection of use in military, mining, demolition, cladding, shock consolidation of powders, shock-induced chemical synthesis and magnetic flux compression processes. The use of distributed initiation locations has emerged as a primary method to customize the detonation front and create desirable output. Explosive/metal systems with multiple, distributed initiation locations create detonation states that do not follow the simple line of sight, or Huygens model and, hence, advanced detonation physics with associated theory are required. The theory of detonation shock dynamics (DSD) is one such description used to provide high fidelity modeling of complex wave structures. A collection of experiments using simultaneous ultra-high speed digital framing and streak film cameras is presented as a means of obtaining spatial and temporal characteristics of complex detonation fronts that validate the DSD descriptions. The method of test, operational conditions and results are given to demonstrate the use of high rate imaging of detonation events and how this validates our understanding of the physics and the capability of advanced detonation wave tracking models.

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Shockwaves, Aero, and Fluid Dynamics

Select this Article		High-speed fluorescence microscopy of cell signaling Howard R. Petty Proc. SPIE 5580, 81 (2005); http://dx.doi.org/10.1117/12.598020 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A high-speed fluorescence microscope was constructed to observe the spatio-temporal dynamics of chemical signals within living cells. Typically, the CCD is gated for <1 microsec. with an ~2 msec. duty cycle to create "stop-action" movies of cells. The fluorescence of endogenous substances and/or exogenous labels was observed. We found that chemical signals travel as waves within cells. These include waves of Ca2+, pH, membrane depolarization and metabolites, which were missed in previous studies because they traverse a cell (d~10 mm) in a time that is much shorter than a typical camera"s shutter speed. Not only are these dynamic chemical structures present in cells, but the initiation points, speeds, locations, and shapes vary. These waves underlie cellular processes such as chemotactic orientation, phagolysosome fusion, phagocytosis, transmembrane signaling, adherence, oxidant production, cell migration, and tumor cell killing. Studies of cell-cell interactions show that immune cells are capable of synchronizing their signaling apparatuses, thus cooperating to mediate target cell destruction. By combining high-speed imaging with conventional biological methods, we have identified novel sites for drug discovery based upon perturbations of chemical waves within cells. We propose that chemical waves in cells travel well-defined pathways at specific times to mediate information transduction, processing and distribution-much like a computer chip.

Select this Article		Low-temperature measurements on shock-loaded tin A. Seifter, M. Grover, D. B. Holtkamp, J. R. Payton, P. Rodriguez, William D. Turley, and A. W. Obst Proc. SPIE 5580, 93 (2005); http://dx.doi.org/10.1117/12.571449 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In an effort to understand the influence of different surface finishes and the effect of ejecta mass on free surface temperature measurements, we performed a series of high-explosively (HE) shocked tin experiments. In this series of experiments the surface finish (i.e, specular, shallow grooves (16 μinch), deep grooves (200 μinch) and "ball-rolled" surfaces) and the ambient atmosphere (from 1.2 torr, to atmospheric air, as well as 1 atm helium) were varied. With a ~180 kbar shock pressure the temperature results agreed for all but the very deep groove (>200 μinch) surfaces investigated.

Select this Article		High-speed photography of microscale blast wave phenomena John M. Dewey and Harald Kleine Proc. SPIE 5580, 106 (2005); http://dx.doi.org/10.1117/12.580096 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract High-speed photography has been a primary tool for the study of blast wave phenomena, dating from the work of Toepler, even before the invention of the camera! High-speed photography was used extensively for the study of blast waves produced by nuclear explosions for which, because of the large scale, cameras running at a few hundred frames per second were adequate to obtain sharp images of the supersonic shock fronts. For the study of the blast waves produced by smaller explosive sources, ever-increasing framing rates were required. As a rough guide, for every three orders of magnitude decrease in charge size a ten-fold increase of framing rate was needed. This severely limited the use of photography for the study of blast waves from laboratory-scale charges. There are many techniques for taking single photographs of explosive phenomena, but the strongly time-dependent development of a blast wave, requires the ability to record a high-speed sequence of photographs of a single event.At ICHSPP25, Kondo et al of Shimadzu Corporation demonstrated a 1 M fps video camera that provides a sequence of up to 100 high-resolution frames. This was subsequently used at the Shock Wave Research Center of Tohoku University to record the blast waves generated by an extensive series of silver azide charges ranging in size from 10 to 0.5mg. The resulting images were measured to provide radius-time histories of the primary and secondary shocks. These were analyzed with techniques similar to those used for the study of explosions from charges with masses ranging from 500 kg to 5 kt. The analyses showed the cube-root scaling laws to be valid for the very small charges, and provided a detailed record of the peak hydrostatic pressure as a function of radius for a unit charge of silver azide, over a wide range of scaled distances. The pressure-radius variation was compared to that from a unit charge of TNT and this permitted a detailed determination of the TNT equivalence of silver azide as a function of peak pressure and radius.The availability of the Shimadzu high-speed framing camera has made it possible to perform experiments at the laboratory scale that previously could be done only on large-scale field trials. At the laboratory scale, many experiments can be performed on the same day, as compared to the months or even years required for the preparation of large-scale field experiments. The economic savings are even greater.

Select this Article		Visualization of tabbed sonic jets Shibu Clement and Ethirajan Rathakrishnan Proc. SPIE 5580, 115 (2005); http://dx.doi.org/10.1117/12.579103 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract This work aims at understanding the physics governing the effect ofmechanical tabs on the vortical structures in the near field of jet mixing region. Jets from a sonic nozzle with and without tabs operated at nozzle pressure ratios from 2 to 7 were studied in the present investigation. Tabs with various combinations of length to widthratios were investigated by keeping the blockage area constant. The tabs offered a blockage of 10.18 percent of nozzle exit area. It was found that when the tabs are introduced, two pairs of counter rotating streamwise vortices are shed all along the edges of the tabs and these vortices act as effective mixing promoters. It is evident from centerline pitot pressure decay that, for the tabbed jet a maximum core reduction of 75% was achieved for NPR 7 compared to uncontrolled jet. Direct shadowgraph technique was employed to capture the waves in the controlled and uncontrolled jets. It showed that the tabs are effective in weakening the shock structure in the jet core. To gain aninsight into the jets spread rate and the distortion of tabbed jets a surface flow visualization method was developed and employed. Presence of two pairs of streamwise vortices in the vicinity of nozzle exit and the bifurcation of the jet field at the downstream for the tabbed jets were also captured by the surface coating technique.

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High-Speed Photography and Applications

Select this Article		Pioneers of high-speed photography and motion analysis Graham P. Haddleton Proc. SPIE 5580, 126 (2005); http://dx.doi.org/10.1117/12.567063 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In many ways this paper continues from the one presented at the 25th ICHSPP held in Beaune, France in 2002. That paper was on Etienne-Jules Marey, a true pioneer of high speed photographic techniques and cinematography, who was born in Beaune.Whilst researching for that paper the author became fascinated by the efforts and results of many pioneers in the field at the turn of the 19th century.

Select this Article		Applications for high-speed infrared imaging Austin A. Richards Proc. SPIE 5580, 137 (2005); http://dx.doi.org/10.1117/12.581293 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The phrase high-speed imaging is generally associated with short exposure times, fast frame rates or both. Supersonic projectiles, for example, are often impossible to see with the unaided eye, and require strobe photography to stop their apparent motion. It is often necessary to image high-speed objects in the infrared region of the spectrum, either to detect them or to measure their surface temperature. Conventional infrared cameras have time constants similar to the human eye, so they too, are often at a loss when it comes to photographing fast-moving hot targets. Other types of targets or scenes such as explosions change very rapidly with time. Visualizing those changes requires an extremely high frame rate combined with short exposure times in order to slow down a dynamic event so that it can be studied and quantified. Recent advances in infrared sensor technology and computing power have pushed the envelope of what is possible to achieve with commercial IR camera systems.

Select this Article		Quasi-monochromatic cerium flash angiography Eiichi Sato, Rudolf Germer, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Toshio Ichimaru, Shigehiro Sato, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 146 (2005); http://dx.doi.org/10.1117/12.567575 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The cerium target plasma flash x-ray generator is useful in order to perform high-speed enhanced K-edge angiography using cone beams because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast mediums. In the flash x-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash x rays are produced by the discharging. The x-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current were approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic x-ray intensities of cerium increased. The K lines were clean and intense, and hardly any bremsstrahlung rays were detected at all. The x-ray pulse widths were approximately 100 ns, and the time-integrated x-ray intensity had a value of approximately 10 μC/kg at 1.0 m from the x-ray source with a charging voltage of 80 kV. In the angiography, we employed a film-less computed radiography (CR) system and iodine-based microspheres.

Select this Article		Air-bubble entrapment due to a drop Nao Ootsuka, Takeharu G. Etoh, Kohsei Takehara, Sachio Oki, Yasuhide Takano, Yuya Hatsuki, and Sigurdur T. Thoroddsen Proc. SPIE 5580, 153 (2005); http://dx.doi.org/10.1117/12.566172 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In 2001, an ultra-high-speed video camera of 1,000,000 frames per second was developed in Hydraulics Laboratory of Kinki University. The image sensor of the camera was the ISIS-V2, the In-situ Storage Image Sensor-Version 2. The camera has been applied to visualization of high-speed phenomena in various fields of science and engineering. We observed entrapment phenomena of bubbles resulting from thermal spraying of metals. Thermal spraying is used to improve solid surfaces by spraying melted metal or ceramic particles to the surfaces. One of the problems relating to the thermal spraying is entrapment of air bubbles under the metal or ceramic layers covering the solid surfaces. The bubbles decrease bonding strength of the layers made by the thermal spraying. The entrapment processes were successfully visualized by application of the ultra-high-speed video camera.

Select this Article		Application of high-speed photography methods to the studies of the plasma sheath structure in plasma-focus phenomenon Krzysztof J. Tomaszewski, Jacek Kaczmarczyk, Marian Paduch, and Ewa Zielinska Proc. SPIE 5580, 163 (2005); http://dx.doi.org/10.1117/12.575269 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents the two methods enabling to determine distributions of electron density and/or electron temperature of the plasma sheath originating in plasma-focus phenomenon. These methods are based on theoretical considerations and processing of experimental results taken by means of high-speed frame photography in narrow band of visible spectrum and multi-frame laser interferometry. Both high-speed photography subsystems can operate simultaneously with sub nanosecond accuracy and allow recording frame sequence of plasma with temporal resolution of about 1 ns and spatial resolution of about 0.1 mm. They are also equipped with digital readout. The detailed explanations and considerations concerning presented methods are exemplified by results obtained in experimental investigations.

Select this Article		Full-field dynamic deformation and strain measurements using high-speed digital cameras Timothy E. Schmidt, John Tyson, Konstantin Galanulis, Duane M. Revilock, and Matthew E. Melis Proc. SPIE 5580, 174 (2005); http://dx.doi.org/10.1117/12.567142 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Digital cameras are rapidly supplanting film, even for very high speed and ultra high-speed applications. The benefits of these cameras, particularly CMOS versions, are well appreciated. This paper describes how a pair of synchronized digital high-speed cameras can provide full-field dynamic deformation, shape and strain information, through a process known as 3D image correlation photogrammetry. The data is equivalent to thousands of non-contact x-y-z extensometers and strain rosettes, as well as instant non-contact CMM shape measurement. A typical data acquisition rate is 27,000 frames per second, with displacement accuracy on the order of 25-50 microns, and strain accuracy of 250-500 microstrain.High-speed 3D image correlation is being used extensively at the NASA Glenn Ballistic Impact Research Lab, in support of Return to Flight activities. This leading edge work is playing an important role in validating and iterating LS-DYNA models of foam impact on reinforced carbon-carbon, including orbiter wing panel tests. The technique has also been applied to air blast effect studies and Kevlar ballistic impact testing. In these cases, full-field and time history analysis revealed the complexity of the dynamic buckling, including multiple lobes of out-of-plane and in-plane displacements, strain maxima shifts, and damping over time.

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Applications in High-Speed Imaging I

Select this Article		Planar velocity and scalar concentration measurements in shock-accelerated unstable fluid interfaces Cherie Goodenough, Sanjay Kumar, Mark Marr-Lyon, Adam Boyts, Katherine Prestridge, Paul Rightley, Christopher Tomkins, Michael Cannon, James Kamm, William Rider, Cindy Zoldi-Sood, Greg Orlicz, and Peter Vorobieff Proc. SPIE 5580, 186 (2005); http://dx.doi.org/10.1117/12.577110 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We report applications of several high-speed photographic techniques to diagnose fluid instability and the onset of turbulence in an ongoing experimental study of the evolution of shock-accelerated, heavy-gas cylinders. Results are at Reynolds numbers well above that associated with the turbulent and mixing transitions. Recent developments in diagnostics enable high-resolution, planar (2D) measurements of velocity fields (using particle image velocimetry, or PIV) and scalar concentration (using planar laser-induced fluorescence, or PLIF). The purpose of this work is to understand the basic science of complex, shock-driven flows and to provide high-quality data for code validation and development. The combination of these high-speed optical methods, PIV and PLIF, is setting a new standard in validating large codes for fluid simulations. The PIV velocity measurements provide quantitative evidence of transition to turbulence. In the PIV technique, a frame transfer camera with a 1 ms separation is used to image flows illuminated by two 10 ns laser pulses. Individual particles in a seeded flow are tracked from frame to frame to produce a velocity field. Dynamic PLIF measurements of the concentration field are high-resolution, quantitative dynamic data that reveal finely detailed structure at several instances after shock passage. These structures include those associated with the incipient secondary instability and late-time transition. Multiple instances of the flow are captured using a single frame Apogee camera and laser pulses with 140 ?s spacing. We describe tradeoffs of diagnostic instrumentation to provide PLIF images.

Select this Article		Experimental investigation of the stress wave propagation along a single straight chain of photo-elastic discs Alexander M. Britan, Beni Glam, Ozer Igra, and Gabi Ben-Dor Proc. SPIE 5580, 193 (2005); http://dx.doi.org/10.1117/12.568543 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The propagation of stress waves through a chain of discs has been studied experimentally using a high-speed photoelastic diagnostic technique and strain gauge measurements. An optically transparent single straight chain of 20-mm diameter discs, made of epoxy, was impacted in a vertical shock tube by an air shock wave. The fringe patterns of the stress field were recorded using a Q-switched YAG laser, a transmission polariscope and a CCD cameras. The incident shock wave reflected head-on from a puncher plate that was placed on top of the discs chain inducing behind it a fairly uniform step-wise pressure pulse. The duration of this pressure pulse acting over the puncher surface lasted for about 6 ms. Experiments indicated that inside the discs-chain the step-wise pressure pulse was broken into several oscillating cycles composed of transmitted and reflected stress waves that were followed by transmitted and reflected rarefaction waves. The back and forth bouncing of these waves continued until the overall stress within the discs-chain reached equilibrium with the compression force acting on the puncher plate. The stress wave propagation velocity along the discs chain was significantly lower than the appropriate speed of sound of the material from which the discs were made.

Select this Article		High-speed photographic investigation of underwater shock wave due to electric pulse power Masahiko Otsuka, Kouhei Inoue, and Shigeru Itoh Proc. SPIE 5580, 203 (2005); http://dx.doi.org/10.1117/12.568803 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In recent years, researches of high energy emitted in a short time are performed actively. The high energy is used for manufacturing and forming. The propagation velocity of the reaction in a high energy explosive may reach the maximum about 10 km/s, and may be accompanied by the shock wave. Many products using the high pressure r the shock wave produced by explosion of explosives are put in practical use. However, a legal restriction to use explosives is severe and needs many efforst for qualification acquisition for handling, maintenance, and security. It is simple to generate shock wave by electric pulse power, instead.In this study, when the shock large current was discharged for electrode, the underwater shock wave generated from electrode was investigated. Furthermore, when attaching metal wires with electrode, the shock large current was passed through metal wires and electrode. We compared the underwater shock wave generated from electrode and electrode with metal wire.The shadowgraph system and a high-speed camera (IMACON468 of HADLAND PHOTONICS, interframe times 10ns to 1ms in 10ns steps independently variable, number of channels framing:4 streak:1) were used to observe the underwater shockwave. The recorded a framing photograph and also by a streak photograph. The shadowgraph method is to observe and project the shadow of the light by density change on a screen or the film of a camera, and is also called direct projective technique.Firstly, we evaluated the explosion power of metal wire. When the shock large current was passed through a metal wire, we investigated underwater shock wave generated from metal wire using high-speed camera. The shock wave velocity and the peak pressure were obtained by using a streak photograph. It seems taht a strong shcok wave is obtained, if the bold wire using a mass condenser bank is exploded.Secondly, we observed underwater shock wave generated by discharge from electrode. When optical observation of the underwater shock wave was performed about the equipment which crushes a structure and a rock by sparking the shock large current, having generated the underwater shock wave near the sound velocity of water continuously at intervals of about 5 μs was checked. Since a continuous wave generated, it is possible that the action time rise for a structure and a rock. Although a peak pressure value was not so high, it is possible that impulse to a structure can improve and it can crush a structure by the impulse rise.

Select this Article		Small glass particle cloud generation induced by laser ablation Kunihito Nagayama, Yuriko Kotsuka, Motonao Nakahara, and Shiro Kubota Proc. SPIE 5580, 212 (2005); http://dx.doi.org/10.1117/12.567873 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Burst of small fragments of glass has been evidenced in the present study, when ground glass surface is laser ablated. Production of macro particles by laser ablation is an inherent characteristic of ground glass, and no similar phenomena have been observed in case of metal or polymer ablation. In this case, no additional metal coating has been made to further enhance absorption of laser pulse. Pulse laser shadowgraph has been taken to study the details of the phenomena in air and in vacuum. At least in vacuum, particle burst is found almost normal to the surface. By using ns-duration Nd:YAG laser of 100 mJ/pulse, observed particle velocity ranges 0.5 km/s to 1.5 km/s in case of in air and the maximum velocity is extended up to 1.5-2 km/s in vacuum. SEM observation of the ground surface reveals that glass surface is covered with micro cracks with several microns deep, which might attribute to macro particle production. In this sense, not surface roughness but also surface structure will be important in the ablation phenomena of glass. It is plausible that absorption of laser beam at the glass surface causes spallation like phenomena as well as production of an amount of plasma, and the plasma production might be responsible for the acceleration of broken fragments of glass. We applied the phenomena to ignite PETN powder explosive, and succeeded in igniting PETN powder only by laser ablation of ground glass.

Select this Article		Schlieren visualization of fluid dynamics phenomena during phacosonication in cataract surgery Gabriella Serafino, Barbara Piuzzi, G. Sanguinetti, C. Sirotti, Paolo Sirotti, and D. Tognetto Proc. SPIE 5580, 217 (2005); http://dx.doi.org/10.1117/12.579670 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In ultrasonic phacoemulsification during cataract surgery the lens material fragmentation has been described as being caused by a combination of several mechanisms. The different theories involve tip vibration, acoustic waves produced by the tip, particles and liquids impact on the surface of the lens and cavitation. However the mechanisms are still not clear. To better understand phaco-related phenomena we have tried to produce a description in term of images of the cataract phacoemulsification procedure. An expanded and collimated laser diode beam transilluminates a transparent tube containing a liquid medium. The machine is activated separating the different phases of irrigation, aspiration and phacosonication. Fluid turbulences and phenomena related to the tip vibration constitute the phase images, visualized using Schlieren or similar techniques. The optical Fourier transform is filtered by a blade or by a black dot. The filtered transform is reconstructed into the visualized phase image and this is acquired by a digital image processing system. The presence of acoustic cavitation and possibly of ultrasonic radiation has been revealed.The technique promises to be a possible means for evaluation of single phaco apparatus power setting and comparison between different machines in terms of power modulation and cavitation production.

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High-Speed Solid State Sensors and Circuits I

Select this Article		Hybrid image sensor with multiple on-chip frame storage for ultrahigh-speed imaging Vincent M. Douence, Yibin Bai, Hakan Durmus, Atul B. Joshi, Per-Olov Pettersson, Debashish Sahoo, Kris Kwiatkowski, Nicholas S. King, Christopher Morris, and Mark D. Wilke Proc. SPIE 5580, 226 (2005); http://dx.doi.org/10.1117/12.567552 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A high-resolution hybrid visible imager, that is composed of a CMOS readout integrated circuit (ROIC) and a silicon photo-detector array, has been designed. The ROIC is fabricated with a standard 0.25 μm CMOS mixed-mode process with a back-illuminated silicon detector array that is produced at Rockwell Scientific Company (RSC) using RSC's HyViSI^TM process.The camera system is designed primarily to record images formed on a scintillator used in pulsed proton radiography experiments. In such experiments, the repetition rate of the proton beam can be as high as 2.8 MHz (358 ns). An imaging system with the desired 1440x1440 pixels resolution would result in an instantaneous readout rate in excess of 5.79 E12 samples/s. To address this issue we designed a pixel with three-frame in-pixel analog storage allowing for a deferred slower readout.The 26 μm pitch pixel imager is operated in a global shutter mode and features in-pixel correlated double sampling (CDS) for each of the three acquired frames. The CDS operation is necessary to overcome the kTC noise of the integrating node to achieve high dynamic range. A 65 fps continuous readout mode is also provided. The hybridized silicon array has close to 100% fill factor while anti-reflection (AR) coating maximizes its quantum efficiency at the scintillator emission wavelength (~415 nm).The ROIC is a 720x720, two-side buttable integrated circuit with on-chip 12-bit analog to digital converter (ADC) for digital readout. Timing and biasing are also generated on-chip, and special attention has been given to the power distribution of the pixel-array and snapshot signal buffers. This system-on-chip approach results in a compact and low power camera, an important feature to extend the number of imaged frames by synchronizing multiple cameras.

Select this Article		A solid state streak camera Stuart Kleinfelder, Kris Kwiatkowski, and Ashish Shah Proc. SPIE 5580, 235 (2005); http://dx.doi.org/10.1117/12.579370 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A monolithic solid-state streak camera has been designed and fabricated in a standard 0.35 μm, 3.3V, thin-oxide digital CMOS process. It consists of a 1-D linear array of 150 integrated photodiodes, followed by fast analog buffers and on-chip, 150-deep analog frame storage. Each pixel's front-end consists of an n-diffusion / p-well photodiode, with fast complementary reset transistors, and a source-follower buffer. Each buffer drives a line of 150 sample circuits per pixel, with each sample circuit consisting of an n-channel sample switch, a 0.1 pF double-polysilicon sample capacitor, a reset switch to definitively clear the capacitor, and a multiplexed source-follower readout buffer. Fast on-chip sample clock generation was designed using a self-timed break-before-make operation that insures the maximum time for sample settling. The electrical analog bandwidth of each channels buffer and sampling circuits was designed to exceed 1 GHz. Sampling speeds of 400 M-frames/s have been achieved using electrical input signals. Operation with optical input signals has been demonstrated at 100 MHz sample rates. Sample output multiplexing allows the readout of all 22,500 samples (150 pixels times 150 samples per pixel) in about 3 ms. The chip"s output range was a maximum of 1.48 V on a 3.3V supply voltage, corresponding to a maximum 2.55 V swing at the photodiode. Time-varying output noise was measured to be 0.51 mV, rms, at 100 MHz, for a dynamic range of ~11.5 bits, rms. Circuit design details are presented, along with the results of electrical measurements and optical experiments with fast pulsed laser light sources at several wavelengths.

Select this Article		Color video camera capable of 1,000,000 fps with triple ultrahigh-speed image sensors Hirotaka Maruyama, Hiroshi Ohtake, Tetsuya Hayashida, Masato Yamada, Kazuya Kitamura, Toshiki Arai, Kenkichi Tanioka, Takeharu G. Etoh, Jun Namiki, Tetsuo Yoshida, Hiromasa Maruno, Yasushi Kondo, Takao Ozaki, and Shigehiro Kanayama Proc. SPIE 5580, 244 (2005); http://dx.doi.org/10.1117/12.567322 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We developed an ultrahigh-speed, high-sensitivity, color camera that captures moving images of phenomena too fast to be perceived by the human eye. The camera operates well even under restricted lighting conditions. It incorporates a special CCD device that is capable of ultrahigh-speed shots while retaining its high sensitivity. Its ultrahigh-speed shooting capability is made possible by directly connecting CCD storages, which record video images, to photodiodes of individual pixels. Its large photodiode area together with the low-noise characteristic of the CCD contributes to its high sensitivity. The camera can clearly capture events even under poor light conditions, such as during a baseball game at night. Our camera can record the very moment the bat hits the ball.

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High-Speed Imaging Techniques I

Select this Article		Carl Cranz, his contemporaries, and high-speed photography Peter W. W. Fuller Proc. SPIE 5580, 250 (2005); http://dx.doi.org/10.1117/12.572038 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Carl Cranz is probably considered primarily as a pioneer in theoretical ballistics, however, in his many experiments he made extensive use of high speed photography to assist in experimentation and data gathering. His basic precept was that the secrets of physics could only be properly discovered by systematic experimental studies and meticulous measurement. This would then by followed by theoretical study to explain the experimental results. By alternate theoretical speculation and practical verification the final truths would be revealed. He invented and pioneered several important photographic systems, probably the most well known being the Cranz-Schardin multi spark system. He became very involved in the sutdy of the flow about high-speed projectiles. He innovated the use of dedicated ballistic tes facilities in which not only the basic range facilities were available, but where all the associated measuring systems were also built in. In this area, his lead was followed by other countries and many similar facilities such as those at BRL in the United States and in England and Europe were soon constructed following the same broad principles. He had many famous contemporaries including E Mach, H Schardin, and H Prandl. He was very careful to keep meticulous notes, which he later reproduced in many papers and also in a book on theoretical and practical ballistics, which became a standard text in the field. This paper gives a short description of his career and interests and also describes some of the photographic systems used by himself and other contemporaries to obtain data.

Select this Article		High-speed and high-resolution color imaging system combined with multispectral optics: optical layout and feasibility study for combustion analysis Shinji Takeuchi, Yoshio Ohno, Kenji Mitsui, and Masataka Arai Proc. SPIE 5580, 261 (2005); http://dx.doi.org/10.1117/12.567324 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The conventional color video image was regarded as a compound image representing energy distributions of three wavelengths such as R.G.and B. These wavelengths were convenient to reconstruct the natural color images. However each of these representative wavelengths could not have clear information concerning self-luminescence events like combustion phenomena. A high-speed video optical system, so called "Multi-Spectral Optics" which had four optical paths for objective wavelengths was developed. The principle of the optics was a new simple multi-spectral beam splitting optics to obtain four images of different wavelengths. By setting the wavelengths as to correspond to representative wavelengths of self-luminescence event, many kinds of information could be derived by image-analysis of among four images captured by this system. The optical system developed here and its feasibility study in combustion analysis are reported in this paper.

Select this Article		Pulsed broadband incoherent illumination for high-speed and ultrahigh-speed imaging Robert G. Root Proc. SPIE 5580, 270 (2005); http://dx.doi.org/10.1117/12.567437 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Short exposure times enable images to capture extremely high-speed motion. Two illumination systems that support imaging with short exposure times are discussed in this paper. The MegaSun plasma discharge illumination system for ultrahigh-speed imaging (approximately 1 million frames per second (fps)) was described at the previous Congress. It provides a single "long" pulse of broadband light sufficient to replace argon candles; the pulse duration can be adjusted to provide uniform illumination for the required number of frames (typically 30 μs to 60 μs) and rapidly extinguishes thereafter. This paper presents the optical and electrical features of a larger energy version of the system, the Super MegaSun, powering new lamp configurations. It provides a full width half maximum (FWHM) pulse of 90 μs. Short exposure times that freeze fast motion are also useful for high-speed framing cameras imaging fast events at rates from 500 fps to several thousand fps. A repetitively pulsed strobe was previously demonstrated that provided short pulses (a few microseconds) at up to 1850 fps synchronized with a film camera for a special test scenario. Some variations of this system that may have more general application are also discussed in this paper.

Select this Article		Application K008 camera within LIDAR for laser sounding of water width from air Vitaly B. Lebedev, Grigory G. Feldman, Alexander O. Vardanyan, Armen A. Nazaryan, Ashot A. Tsovyan, Yury A. Yedigaryan, and Sergey S. Melikyan Proc. SPIE 5580, 282 (2005); http://dx.doi.org/10.1117/12.567413 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The report gives the result of image K008 camera/1, 2/ application in trial experiments on laser sounding of water width from the air to determine the possibility of detecting and identifying objects dipped into the water and in the future for detecting and identifying objects dipped into the water and in the future for detecting a parasitic water-plant in the Sevang Lake in Armenia and drawing a map of its distribution across the depth throughout aquatory of the Lake.

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High-Speed Solid State Sensors and Circuits II

Select this Article		CMOS active pixel image sensor with in-pixel CDS for high-speed cameras Toru Inoue, Shinji Takeuchi, and Shoji Kawahito Proc. SPIE 5580, 293 (2005); http://dx.doi.org/10.1117/12.567313 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper presents a high-speed CMOS image sensor whose frame rate exceeds 2000 frames/sec (fps). The pixel includes a photodiode, a charge-transfer amplifier, and circuitry for correlated double sampling (CDS) and global electronic shuttering. Reset noise, which is the major random noise factor, is reduced by the CDS combined with the charge-transfer amplifier. The total number of devices in the pixel is 11 transistors and 2 MOS capacitors. Test circuits were fabricated using the 0.25 um CMOS process. The sensitivity of the 20 x 20 um² pixel using the floating diffusion capacitor of 6.2 fF and the photodiode area of 15 x 12.7 um^2 is 34 V/lux-sec. At 1000 fps, noise level is 2.43 mVrms (dark). The noise level and the sensitivity are greatly improved compared to the non-charge-transfer pixel without global shutter (3Tr-type) implemented with the same technology, and to a previous version of the APS with in-pixel CDS.

Select this Article		An image sensor of 1 Mfps with photon counting sensitivity Takeharu G. Etoh and Hideki Mutoh Proc. SPIE 5580, 301 (2005); http://dx.doi.org/10.1117/12.566170 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract For application of a video camera of 1,000,000 fps, developed by the authors in 2001, to electron microscopes and biological microscopes, a next generation ultra-high-speed image sensor with photon-counting sensitivity is proposed. It is based on three key technologies, i.e., (1) ISIS, the In-situ Storage Image Sensor for ultra-high-speed continuous image capturing, invented by the authors, (2) CCM, the Charge Carrier Multiplication by impact ionization, invented by Hynecek, and (3) conventional back-side illuminated CCD. It works not only for ultra-high-speed and ultra-high-sensitive image capturing, but also for image capturing under illumination of ultra-violet, visible, and near-infrared lights, soft X-ray and electron beam. The sensor is named the PC-ISIS, the photon-counting ISIS. The concept of the PC-ISIS is presented. Difficulties in the realization of the PC-ISIS are discussed.

Select this Article		High-speed camera with internal real-time image compression Michel Paindavoine, Romulad Mosqueron, Julien Dubois, Cedric Clerc, Jean-CLaude Grapin, Lionel Pierrefeu, and Francois Tomasini Proc. SPIE 5580, 308 (2005); http://dx.doi.org/10.1117/12.570456 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract High-speed video cameras are powerful tools for investigating, for instance, fluid dynamics or the movements of mechanical parts in manufacturing processes. In the past 5 years the use of CMOS sensors instead of CCDs has facilited the development of high-speed video cameras offering digital outputs, readout flexibility, and lower manufacturing costs. Still the huge data flow provided by the sensor cannot be easily transferred or processed and thus must generally be stored temporarily in fast local RAM. Since this RAM is size limited, the recording time in the camera is only a few seconds long. We tried to develop an alternative solution that would allow continuous recording. We developed a real-time image compression in order to reduce the data flow. We tested three algorithms: run-length encoding, block coding, and compression using wavelets. These compression algorithms have been implemented into a FPGA Virtex II-1000 and allow real-time compression factors between 5 and 10 with a PSNR greater than 35dB. This compression factor allowed us to link a new high-speed CMOS video camera with a PC using a single USB2 connection. The full flow of 500 fps in 1280x1024 format is transferred to the computer in real-time.

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High-Speed Imaging Techniques II

Select this Article		Visualization of optical pulse filamentation by femtosecond time-resolved optical polarigraphy Martin Centurion, Ye Pu, and Demetri Psaltis Proc. SPIE 5580, 320 (2005); http://dx.doi.org/10.1117/12.584170 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We have observed the filamentation of optical pulses in carbon disulfide(CS2) using femtosecond time-resolved optical polarigraphy(FTOP). A pump-probe setup is used to capture the propagation of a 150 femtosecond laser pulse in CS2. The probe pulse propagates in a direction perpendicular to the pump. The high intensity of the pump pulse causes a transient index change in the material through the Kerr effect. The induced birefringence is proportional to the intensity of the pump and can be captured by monitoring the polarization of the probe. The probe pulse is imaged on a CCD camera to recover the intensity profile of the pump pulse. We have used this technique to observe the spatial evolution of the pulse as a function of power and propagation distance. Initially, the pulse propagation causes a coarse redistribution of the intensity. The beam then breaks up into stable light filaments which propagate for several millimeters, and finally the beam profile becomes unstable to small fluctuations in the input power.

Select this Article		Computer modeling of a subfemtosecond photoelectron gun with time-dependent electric field for TRED experiments Mikhail A. Monastyrskiy, Sergey V. Andreev, Dmitry E. Greenfield, Gennadii I. Bryukhnevich, Victor A. Tarasov, and Mikhail Y. Schelev Proc. SPIE 5580, 324 (2005); http://dx.doi.org/10.1117/12.567644 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the paper, theoretical and numerical studies on temporal focusing of photoelectron bunch in time-dependent fields are continued. Presented are the results of computer modeling on electron-optical system with combined time-dependent electric and static magnetic fields to ensure both spatial focusing and temporal compressing of photoelectron bunch down to sub-femtosecond level. The peculiarity of space charge effect contribution to the bunch broadening in the case of time-dependent electric field is discussed.

Select this Article		Visualization of laser-induced liquid micro-jet disintegration by means of high-speed video stroboscopy Boleslaw Stasicki, Ales Charvat, Manfred Faubel, and Bernd Abel Proc. SPIE 5580, 335 (2005); http://dx.doi.org/10.1117/12.567439 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the present paper we describe a novel approach to monitor and to investigate laser induced liquid water jet disintegration in air and in vacuum. The features of liquid beam disintegration in vacuum are of importance for pulsed laser induced liquid beam desorption mass spectrometry and micro-calorimetry. Due to the small liquid beam diameter of 12-15 μm, its high speed of 50-100 m/s, and a total event duration of a less than a few microseconds only, the microscopic visualization of the jet disintegration was a challenging task. Good quality video sequences have been recorded with a high-speed video stroboscope system running in the back illumination mode. The light pulses were synchronized carefully with the shutter circuit of the stroboscope camera and the IR-laser pulses. With a continuously changing time delay between the desorption laser pulses and the shutter opening a slow-motion effect has been achieved. The delay was changed in steps of 25 ns which corresponds to an equivalent framing speed of about 40,000,000 fps. With a high-brightness light emitting diode (LED) as a light source an exposure time of about 200 ns an effective time resolution of several hundred nanoseconds could be achieved. Using a pulsed Nd:YAG laser instead, the exposure time and time resolution could be reduced down to about 10 ns and 25 ns, respectively. Due to the well known speckle problem when using coherent light sources for illumination we have finally used a Nd:YAG laser excited dye solution of Rhodamine 6G (10-3 M) in methanol solution in a quartz cuvette placed in front of the liquid beam keeping the short exposure time of about 10 ns. In this nearly speckle free visualization mode the real-time slow-motion imaging of the jet disintegration and the study of the desorption process has been made possible with a time resolution of 25 ns (currently limited by the phase shifter steps) and an exposure time of ~10 ns only. It has been found that the laser induced desorption is so fast that the measurement in the gas phase represents a "snapshot" of the situation (structure, complexation, interaction) in solution. The new desorption technique enables very promising studies of the function, structure and interaction of biopolymers in their natural environment.

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Applications in High-Speed Imaging II

Select this Article		Scalar measurements in a flickering flame using high-speed rainbow schlieren deflectometry Tommy Wong and Ajay K. Agrawal Proc. SPIE 5580, 347 (2005); http://dx.doi.org/10.1117/12.571252 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Rainbow schlieren apparatus was integrated with a high-speed digital imaging system to quantify the scalar structure of steady and flickering jet diffusion flames of gaseous hydrogen. The rainbow schlieren technique utilizes a continuously graded color filter placed at the focal point of the decollimating lens to quantify the transverse displacement of light rays passing through the media. Excellent agreement was reached between steady flame shapes determined from the schlieren technique and direct visualization. For the flickering flame at jet exit Reynolds number of 300, the rainbow schlieren images were taken at acquisition rates of up to 1000 frames per second. The image data were analyzed to determine full-field distributions of refractive index, and hence, temperature and oxygen concentration assuming chemical equilibrium in the flame. The contour plots of instantaneous temperature and oxygen concentration are shown to quantitatively describe the flow structure during a flicker cycle. Results show that the capability to quantitatively describe the temporal evolution of the temperature field is greatly improved by using the high-speed imaging system.

Select this Article		High-speed close-range photogrammetry for dynamic shape measurement Iain D. Wallace, Nicholas J. Lawson, Andrew R. Harvey, Julian D. Jones, and Andrew J. Moore Proc. SPIE 5580, 358 (2005); http://dx.doi.org/10.1117/12.567331 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We describe and characterize an experimental arrangement to perform shape measurements on a deformable object through dynamic close-range photogrammetry; specifically, an insect in flight. The accuracy of shape measurements in photogrammetry is improved by increasing the number of camera views. In static close-range photogrammetry, one may increase the number of camera views by moving the camera and taking a number of images, or equivalently, by moving the object. In dynamic close-range photogrammetry of rigid objects, one may combine all the camera views from a video sequence. However, in dynamic close-range photogrammetry of a deformable object, the number of camera views is restricted to the number of physical cameras available. The technique described here is to arrange a number of cameras around a measurement volume, illuminated by a laser synchronized to the cameras. The cameras are first calibrated, and then a bundle adjustment is used to determine point positions on the object. In this paper, we first determine the capabilities of the system in static close-range photogrammetry. We then perform a static shape measurement on our dynamic target and compare this with the results of dynamic close-range photogrammetry. The results indicate that high-speed dynamic measurements of the deformation of insect wings during flight should provide adequate resolution to develop an aeroelastic model of a flapping wing.

Select this Article		High-speed imaging and processing for rail track inspection Dmitry V. Popov and Roman B. Ryabichenko Proc. SPIE 5580, 367 (2005); http://dx.doi.org/10.1117/12.567325 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The safety of railway traffic depends on state of the track. About ten parameters are measured on Moscow Metropolitan for rail control. At present time the contact technology is used that doesn't provide required accuracy, limits speed of movement up to 25 mph and doesn't work in real-time mode.Non-contact photonic measurement system (KSIR) is developed which can works at speeds up to 70 mph.The KSIR consists of four subsystems: rail wear, height and track gauge measurement (BFSM); rail slump measurement (FIP); contact rail measurement (FKR); speed, level and car locating (USI).KSIR contains five CCD matrix cameras, four line CCD cameras, five infrared stripe lasers and four spot infrared lasers. Preliminary image processing is carried out using digital signal processor.The images from cameras are distorted because there is angle between photonic unit and rail. Additional distortions are caused by short-focus optics and small distance between camera and track. This distance is limited by structure clearance. For distortion eliminating is applied the transformation algorithms. It's based on surfaces spline-approximation. As a result the KSIR calculates coefficients of approximating polynomials. The calibration is performed for checking accuracy of measurement in BFSM, FIP and FKR units.

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Streak Optics and Related Issues

Select this Article		Preliminary tests for coherent anti-Stokes Raman spectroscopic measurement of radiation behind strong shock waves Hiroyuki Ando, Katsumi Miyazaki, Kazunori Takada, Kazuhiro Toyoda, and Kazuo Maeno Proc. SPIE 5580, 376 (2005); http://dx.doi.org/10.1117/12.580362 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract When space vehicles reenter onto the atmosphere with velocity over 10 km/s, radiative heating from the shocked air ahead of the vehicle plays an important role on the heat flux to the wall surface as well as convective heating. So far, spectroscopic study has been developed for temperature measurement of radiation behind strong shock waves. In this paper, CARS method (Coherent Anti-Stokes Raman Spectroscopy) for radiation behind strong shock waves in gases has been applied. The CARS measurement system consists of a YAG laser, a dye laser, and high-sensitivity CCD camera systems. The preliminary tests have been performed for the purpose of detecting CARS signal from strong shock waves with velocity range over 5km/s.

Select this Article		A measurement of 3D flow field induced by shock waves using interferometric CT method and numerical analysis Masanori Ota, Toshihiro Koga, Kazuhiro Toyoda, and Kazuo Maeno Proc. SPIE 5580, 384 (2005); http://dx.doi.org/10.1117/12.579712 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Three-dimensional flow phenomena have been observed in a shock tube experiment for shock waves and vortices by using an interferometric CT (Computed Tomography) technique with a N2 pulse laser. A model with small duct, which has a pair of circular open ends, is introduced in a test section of diaphragmless shock tube, and can be rotated around its central axis to change the observation angle. The projection image of density distribution for each observation angle is obtained by using a fixed Mach-Zehnder interferometer. Three-dimensional density distribution is reconstructed from these projection images. The shock Mach number is 2.3 in nitrogen gas of 19.4kPa initial pressure at the exits of the open ends. The resultant 3-D density flow fields are illustrated by several imaging technique to clarify 3-D features of shock waves, vortices, and their mutual interactions. A computational fluid dynamics (CFD) simulation is also applied to the 3-D flow fields. The CFD results can represent density and another properties in flow fields, and these properties are useful for identifying the phenomena. The mutual validation between the experimental CT density results and these CFD results is discussed. Three-dimensional features of flow fields are investigated in detail by analyzing the experimental CT results with CFD results.

Select this Article		Laser-induced dispersion optical filter at 532 nm Yun-Dong Zhang, Xu-Tao Sun, and Zhu-Song He Proc. SPIE 5580, 393 (2005); http://dx.doi.org/10.1117/12.584250 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper, the semi-classical theory was utilized to theoretically analyze K-532nm Laser-induced dispersion optical filter (LIDOF), and theoretical model was given. By solving the density matrix equations, the system induced polarizability was gained, and eventually the transmission spectra were gained by theoretical calculation.

Select this Article		High-speed image-tube photography Mikhail Y. Schelev Proc. SPIE 5580, 399 (2005); http://dx.doi.org/10.1117/12.570406 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Important historical events in high-speed image-tube photography are briefly high highlighted. The unique recording properties of image-tube diagnostics are be once more emphasized. As an example, some recent results on streak tubes application for femtosecond laser spark investigation are presented. It is concluded that the time-depending focusing of photoelectron images is the only way to overcome femtosecond time resolution limit. The present trends in ultrafast image-tube studies are considered in their connection with development of subfemtosecond photoelectron beam sources intended for femto-attosecond photoelectron diffractometry.

Select this Article		The streak camera development program at LLE Paul A. Jaanimagi, Robert Boni, D. Butler, S. Ghosh, William R. Donaldson, and Robert L. Keck Proc. SPIE 5580, 408 (2005); http://dx.doi.org/10.1117/12.602565 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The Diagnostic Development Group at the Laboratory for Laser Energetics has endeavored to build a stand-alone, remotely operated streak camera with comprehensive auto-focus and self-calibration capability. Designated as the Rochester Optical Streak System (ROSS), it is a generic streak camera platform, capable of accepting a variety of streak tubes. The system performance is limited by the installed tube's electron optics, not by any camera subsystem. Moreover, the ROSS camera can be photometrically calibrated.

Select this Article		Dynamic parameters evaluation for femtosecond streak tubes Valentina P. Degtyareva, Gennadii I. Bryukhnevich, V. I. Lozovoi, Mikhail Y. Schelev, Zoya M. Semichastnova, and Nikolai S. Vorobiev Proc. SPIE 5580, 416 (2005); http://dx.doi.org/10.1117/12.569964 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Presented are the experimental results on femtosecond streak tubes measurements in dynamic mode. Several streak tube prototypes have been manufactured, with either distributed coaxial-strip line or capacitor-type photocathode-accelerating mesh assembly. Electrical field transition time in the photocathode-accelerating mesh gap was investigated. Tubes have been tested in a variety of regimes, in order to define the most efficient ones. Dynamic parameters of the developed femtosecond streak tubes were measured inside the streak camera prototype. The following dynamic parameters were evaluated: ultimate time resolution, dynamic range, and signal/noise ratio, spectral range, input sensitivity, streak speed and its nonlinearities, etc. The developed and optimized femtosecond streak tubes represent a reliable basis for design of streak cameras being required for photographic recording of ultrafast events in laser and plasma physics, time-resolved spectroscopy, laser interaction with matter, laser fusion, etc.

Select this Article		High-speed photocathodes fabricated from metallic nanostructures Eduard L. Nolle, Yuri B. Khavin, and Mikhail Y. Schelev Proc. SPIE 5580, 424 (2005); http://dx.doi.org/10.1117/12.568531 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Spectral dependences of photoemission (PE), absorption and reflection from Ag and Au granular films are studied experimentally together with their structure and physical properties using Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPES). It is found that a new intensive PE band in the visible spectral range (l = 500 ÷ 600 nm) appears when such films are activated with Cs and O and this PE band coincides with the absorption and reflection bands. Theoretical calculations of PE spectra based on absorption spectrum of metallic oblate spheroidal nanoparticles are also carried out. Such calculations indicate that the appearance of this PE band can be explained by excitation of the surface plasmons in spheroidal nanoparticles with the major axes approximately equal to 50 nm and minor axes approximately equal to 5 nm. Similar calculations carried out for an S-1 photocathode indicate that the shape and the position of the measured long wavelength PE band with the peak maximum at λ ≈ 800 nm can also be explained by excitation of the surface plasmons in Ag spheroidal nanoparticles with the axes equal to 25 and 0.9 nm correspondingly. Degradation with time of PE from Ag and Au granular films is also studied and it is shown that while Ag nanoparticles degrade due to desorption of Cs, Au nanoparticles degrade due to its adsorption.Photoelectron emission in the studied metallic nanostructures can be explained by the surface photoeffect caused by excitation of the surface plasmons in nanoparticles. Therefore, photocathodes with subfemtosecond-range temporal resolution and quantum yield equal to several percent in the visible wavelength range can be fabricated from such nanostructures.

Select this Article		Diagnostics for laser plasma EUV sources Martin C. Richardson, Chiew-Seng Koay, Kazutoshi Takenoshita, C. Keyser, Robert Bernath, Simi George, and Somsak Teerawattanasook Proc. SPIE 5580, 434 (2005); http://dx.doi.org/10.1117/12.597349 \| Cited 7 times Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A high repetition-rate laser plasma source, possessing distinct radiation and particle emission characteristics, is now a principal candidate light source for the next generation of technology for the fabrication of computer chips. For these sources to satisfy this critical need they will need to meet unprecedented levels of performance, stability and lifetime. We review here some of the principal diagnostics of the EUV radiation that are now being utilized in the metrology, spectroscopy and imaging of these sources.

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Laser Sources and Applications

Select this Article		LIL and LMJ laser facility status Claude Cavailler, Noel A. Fleurot, and Jean-Michel Di Nicola Proc. SPIE 5580, 443 (2005); http://dx.doi.org/10.1117/12.569638 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The French Commissariat a l'Energie Atomique (CEA) began the construction of the Laser Megajoule (LMJ), a 240-beam laser facility, at the CEA laboratory CESTA near Bordeaux. The LMJ will be a cornerstone of the CEA "Programme Simulation", the French analog to the US Stockpile Stewardship Program.The LMJ is designed to deliver 2MJ of 0.35 μm light to targets for high energy density physics experiments and to ultimately obtain ignition and propagating burn with DT targets in the laboratory.The Scientific conception and system design was completed in 1999 and was followed by the Demonstration of an Engineering Prototype which was achieved in early 2003 with operation of one beam of the Ligne d'Integration Laser (LIL) at CESTA, with 9.5 kJ of UV light (0.35 μm) in less than 9 ns from a single laser beam.The Ralization phase of the LMJ facility was initiated in March of 2003 with the construction start of teh building and the target chamber.This paper will present results from the commissioning phase of the LIL program in 2003 and 2004. The activation and commissioning of the full 8 beamlines of LIL over the next 2 years will be part of determining the final specifications and integration and commissioning plans for the LMJ which is expected to demonstrate first light performance through 240 beams by 2010.

Select this Article		High-power diode lasers in spray process diagnostics Jussi Larjo Proc. SPIE 5580, 455 (2005); http://dx.doi.org/10.1117/12.567358 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Spray processes are commonly employed in many kinds of surface treatment applications, most prominently in medical, material processing and manufacturing industries. While spraying is a well established technology, we still lack complete understanding of all interactions within a given spray process. This is because the physical models of many subprocesses, like turbulent gas flow, particle formation and gas-particle interaction, are limited and often provide only qualitative predictions on the real process. Imaging measurements are essential in gaining better understanding of a spray process. They offer a way to measure properties of both the complete spray plume and individual droplets. A spray analysis system typically requires a high-power stroboscopic light source; Xe flashlamps and Q-switched solid state lasers have been the most common choice until recently. The development of high-power diode lasers has provided a versatile, low-cost and easy to use light source for the analysis of spray processes. We present a real-time diode laser based imaging system to measure droplet density, size and velocity distributions in a spray, together with the spray plume geometry.

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Shock and Hypersonic Physics

Select this Article		Infrared images of shock-heated tin Craig W. McCluskey, Mark D. Wilke, William D. Turley, Gerald D. Stevens, Lynn R. Veeser, Michael Grover, and Arnold Adams Proc. SPIE 5580, 466 (2005); http://dx.doi.org/10.1117/12.585558 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract High-resolution, gated infrared images were taken of tin samples shock heated to just below the 505 K melting point. Sample surfaces were either polished or diamond-turned, with grain sizes ranging from about 0.05 to 10 mm. A high explosive in contact with a 2-mm-thick tin sample induced a peak sample stress of 18 GPa. Interferometer data from similarly-driven tin shots indicate that immediately after shock breakout the samples spall near the free (imaged) surface with a scab thickness of about 0.1 mm. Images were taken with gate widths of 0.2 to 0.5 μs and start times ranging from 0.3 to 1.5 μs after shock breakout. The camera and experimental techniques were described previously. [S.S. Lutz, et al., Gated IR images of shocked surfaces, in Shock Compression of Condensed Matter-2001, M.D. Furnish, ed., AIP (2002)]. Infrared radiation (3 to 5 μm) from the sample was imaged onto a gated InSb camera array with lens systems capable of resolving features on the order of 0.1 mm. Assuming a dynamic emissivity of 0.1, calculated temperatures were around 700 K for the millimeter-sized hot spots and 450 K in the surrounding area. The images showed different amounts and physical distribution of hot spots. Although there was a trend to more and higher-temperature hot spots with larger grain size, the hot spots do not appear to map directly to individual gain shapes or boundaries.

Select this Article		Biological material imaging using THz-echo analysis method Feng Huang, John F. Federici, Robert Barat, and Dale E. Gary Proc. SPIE 5580, 477 (2005); http://dx.doi.org/10.1117/12.584191 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Ultrafast laser techniques have opened up a tremendous research opportunity in studying the interaction of short pulses of light with matter. With discovering of the picosecond photoconducting hertzian dipoles and high-brightness THz beams characterized with an ultrafast detector, we have seen more and more applications of ultrafast light in non-invasive imaging. Standard methods, when applied to the measurement of thin optical materials, doesnot independently determine the material's thickness and index of refraction. The proposed method is fundamentally different from other imaging such as contrast difference in optical coherent tomography (OCT) or the peak-to-peak intensity ratio as in THz imaging to determine index of refraction and thickness. We show that the application of ultrafast techniques allows simultaneous measurements of material thickness and optical constants in optical precision from transmission measurements. Such finding invites new perspectives in imaging and other applicable disciplines such as imaging processing after recording of the THz waveform of biological samples.

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Multispectral Imaging

Select this Article		Pseudo-imaging the spectral-temporal evolution of energetic transient events Melanie M. Weeks, James E. Murguia, Jonathan M. Mooney, Richard J. Nelson, and William S. Ewing Proc. SPIE 5580, 487 (2005); http://dx.doi.org/10.1117/12.583486 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Spectral imaging is the art of quantifying the spectral and spatial characteristics of a scene. The current state of the art in spectral imaging comprises a wide range of applications and sensor designs. At the extremes are spectrometers with high spectral sampling over a limited number of imaging pixels and those with little spectral sampling over a large number of pixels. The predominant technical issue concerns the acquisition of the three-dimensional spectral imagery (X,Y,l) using an inherently two-dimensional imaging array; consequently, some form of multiplexing must be implemented. This paper will discuss a new class of sensors, broadly referred to as Spectral Temporal Sensors (STS), which capture the position and spectra of uncued point sources anywhere in the optical field. These sensors have large numbers of pixels (>512x512) and colors (>50). They can be used to sense explosions, combustion, rocket plumes, LASERs, LEDs, LASER/LED excitations and the outputs of fiber optic cables. This paper will highlight recent developments on an STS that operates in a Pseudo-imaging (PI) mode, where the location of an uncued dynamic event and its spectral evolution in time are the data products. Here we focus on the sensor's ability to locate the event to within approximately 1/20th pixel, however we will also discuss its capabilities at fully characterizing event spectral temporal signature at rates greater than 100Hz over a large field of view (greater than 30°).

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Visualization, Analysis, and Education

Select this Article		Teaching high-speed photography and photo-instrumentation Andrew Davidhazy Proc. SPIE 5580, 497 (2005); http://dx.doi.org/10.1117/12.584130 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract As the tools available to the high speed photographer have become more powerful the underlying technology has increased in complexity and often is beyond the reach of most practitioners in terms of in-the-field troubleshooting or adaptation and this specialization has also driven many systems beyond the reach of high school, community college and undergraduate, non-research funded, universities. In spite of this and with the belief that fundamental techniques, reasoning and approaches have not changed much over the years, several courses in photo-instrumentation at the Imaging and Photographic Technology program at the Rochester Institute of Technology present to a couple dozen undergraduate students a year the principles associated with a various imaging systems and techniques for visualization and data analysis of high speed or "invisible" phenomena. This paper reviews the objectives and philosophy of these courses in the context of a total imaging technology education. It describes and illustrates current topics included in the program. In brief, calibration and time measurement concepts, instantaneous and repetitive time sampling equipment, various visualization technologies, strip and streak cameras and applications using film and improvised digital recorders, basic velocimetry techniques including sensitometric velocimetry and synchro-ballistic photography plus other related techniques are introduced to undergraduate students.

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Interferometry and Holography

Select this Article		Imaging VISAR diagnostic for the National Ignition Facility (NIF) Robert M. Malone, John R. Bower, David K. Bradley, Gene A. Capelle, John R. Celeste, Peter M. Celliers, Gilbert W. Collins, Mark J. Eckart, Jon H. Eggert, Brent C. Frogget, Robert L. Guyton, Damien G. Hicks, Morris I. Kaufman, Brian J. MacGowan, Samuel Montelongo, et al. Proc. SPIE 5580, 505 (2005); http://dx.doi.org/10.1117/12.579285 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The National Ignition Facility (NIF) requires diagnostics to analyze high-energy density physics experiments. A VISAR (Velocity Interferometry System for Any Reflector) diagnostic has been designed to measure shock velocities, shock breakout times, and shock emission of targets with sizes from 1 to 5 mm. An 8-inch-diameter fused silica triplet lens collects light at f/3 inside the 30-foot-diameter vacuum chamber. The optical relay sends the image out an equatorial port, through a 2-inch-thick vacuum window, and into two interferometers. A 60-kW VISAR probe laser operates at 659.5 nm with variable pulse width. Special coatings on the mirrors and cutoff filters are used to reject the NIF drive laser wavelengths and to pass a band of wavelengths for VISAR, passive shock breakout light, or thermal imaging light (bypassing the interferometers). The first triplet can be no closer than 500 mm from the target chamber center and is protected from debris by a blast window that is replaced after every event. The front end of the optical relay can be temporarily removed from the equatorial port, allowing other experimenters to use that port. A unique resolution pattern has been designed to validate the VISAR diagnostic before each use. All optical lenses are on kinematic mounts so that the pointing accuracy of the optical axis can be checked. Seven CCD cameras monitor the diagnostic alignment.

Select this Article		Optical probes for continuous Fabry-Perot velocimetry inside materials David R. Goosman, James T. Wade, Raul Garza, George R. Avara, Thomas R. Crabtree, Anthony T. Rivera, David E. Hare, Danny Tolar, Jr., and Bradford A. Bratton Proc. SPIE 5580, 517 (2005); http://dx.doi.org/10.1117/12.566589 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We have used velocimetry for many years at LLNL to measure velocity-time histories of surfaces in dynamic experiments. We have developed and now use special instrumentation to make continuous shock-velocity measurements inside of materials. The goal is to extend the field of velocimetry into a new field of application in shock physics. At the last Congress we reported the successful use of our new filter system for selectively eliminating most of the non-Doppler-shifted light. We showed one record of a fiber embedded inside an explosive making a continuous detonation velocity-time history. At that time it was difficult to obtain complete records. We have now carried out over 50 inexpensive experiments usually using small cylinders or rectangular blocks of explosives or metals. Most were started by detonating a 25 mm diam. by 25 mm long cylinder of Comp B explosive to drive a shock into an adjacent material of similar dimensions, using our embedded fiber probes. In contrast to surface velocimetry, embedded measurements involve detailed hydrodynamicconsiderations in order to result in a successful record. Calculations have guided us in understanding of various failed and successful experiments. The homogeneity of the explosive, poor contact, the materials used in the cladding and core of the fiber optic probes, and the shock speeds to be covered all greatly affect the success of an experiment. For example, a poor contact between the optical fiber and its environment causes severe loss of data. Non-symmetric air gaps on one side of the fiber cause 3 dimensional hydrodynamic effects, which cause the shock wave in the fiber core to be too steeply angled to reflect light. We have recently developed and successfully used a special probe to usually overcome this limitation. We have custom designed several unique types of fiber-optic probes for specialty applications, using both solid and liquid core materials, to extend the usable shock-velocity range.

Select this Article		Femtosecond holography Martin Centurion, Ye Pu, and Demetri Psaltis Proc. SPIE 5580, 529 (2005); http://dx.doi.org/10.1117/12.584169 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We present a holographic recording technique with 150 femtosecond time resolution. This technique allows us to capture either a single hologram with fine spatial resolution (4 micrometers), or a time-sequence of multiple holograms with reduced spatial resolution in a single-shot experiment, while preserving amplitude and phase information. The time resolution and the frame rate are limited only by the duration of the laser pulses. The holograms are recorded on a CCD camera and digitally reconstructed. We have used the technique to study the nonlinear propagation of high energy femtosecond pulses through liquids. We have observed dramatic differences in the pulse propagation characteristics depending on the strength of the nonlinear coefficient of the material and it's time response. The fine spatial resolution allows us to zoom in and visualize the spatial profile of the pulses breaking up into multiple filaments while the phase recovered from the holograms helps us identify the nonlinear index changes in the material. We have measured both positive and negative index changes. Very fast positive index changes are generally attributable to the Kerr nonlinearity. The negative index changes can be caused by electron plasma generated by multiphoton absorption.

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X-Ray Sources and Recording I

Select this Article		Weakly ionized linear plasma x-ray generator with molybdenum-target triode Eiichi Sato, Yasuomi Hayasi, Rudolf Germer, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Toshio Ichimaru, Shigehiro Sato, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 535 (2005); http://dx.doi.org/10.1117/12.567566 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the plasma flash x-ray generator, a 200 nF condenser is charged up to 50 kV by a power supply, and flash x rays are produced by the discharging. The x-ray tube is a demountable triode with a trigger electrode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Target evaporation leads to the formation of weakly ionized linear plasma, consisting of molybdenum ions and electrons, around the fine target, and intense characteristic x rays are produced. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 16 kA. When the charging voltage was increased, the linear plasma formed, and the K-series characteristic x-ray intensities increased. The K lines were quite sharp and intense. The x-ray pulse widths were approximately 600 ns, and the time-integrated x-ray intensity had a value of approximately 65 μC/kg at 1.0 m from the x-ray source with a charging voltage of 50 kV.

Select this Article		Motion pictures of propagating ultrashort laser pulses Yasuhiro Awatsuji, Aya Komatsu, Masatomo Yamagiwa, and Toshihiro Kubota Proc. SPIE 5580, 543 (2005); http://dx.doi.org/10.1117/12.567035 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We achieved the motion pictures of the ultrashort laser pulses propagating in air and some optical devices using the light-in-flight recording by holography. The pictures are recorded with a ~ 10-ps and a 130-fs pulsed laser, and a photographic plate. To reconstruct the motion pictures, the hologram is illuminated with a continuous wave (cw) laser, and the hologram is moved in parallel to the plane on which the recording material was set. The motion pictures can be also seen in the following two other cases. (1) We move in parallel to the hologram while the hologram is illuminated with a cw laser. (2) We stop to see the hologram scanning the hologram with the cw laser beam. The motion pictures are continuous in terms of both time and space. The reconstruction speed of the motion pictures is determined by the speed of the moving or the scanning. We demonstrate motion pictures of the ultrashort laser pulses going through several optical elements. Fundamental optical phenomena such as reflection, refraction, and diffraction are occurring are observed for the ultrashort laser pulse. We discuss the resolution of the motion pictures.

Select this Article		Use of a grid-structured photocathode to essentially improve temporal resolution in streak tubes Dmitry E. Greenfield Proc. SPIE 5580, 551 (2005); http://dx.doi.org/10.1117/12.567123 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The principle limitation of the temporal resolution in the streak tubes is the first-order temporal aberration rising from the initial energy spread of the photoelectrons. The conventional way to reduce this aberration lays in increasing the near-cathode electric field. However the danger of electric breakdown leads to practical limitation of the field strength and, in its turn, the temporal resolution. Another approach to the problem consists in using a fine-mesh structured photocathode instead of a solid one. The paper presents calculations, both analytical and numerical, which have allowed estimation of required mesh parameters. As the needed mesh period is rather small, the approach under consideration could be hardly brought into practice until the nowadays advance in microelectronics and micromechanics.

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X-Ray Sources and Recording II

Select this Article		Novel x-ray imaging diagnostics of high-energy nanosecond pulse accelerators Graham W. Smith, David E. Beutler, John D. Bell, Calvin L. G. Seymour, Robert J. Hohlfelder, Roque R. Gallegos, and John Dudley Proc. SPIE 5580, 559 (2005); http://dx.doi.org/10.1117/12.565136 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Pioneering x-ray imaging has been undertaken on a number of AWE"s and Sandia National Laboratories" radiation effects x-ray simulators. These simulators typically yield a single very short (<50ns) pulse of high-energy (MeV endpoint energy bremsstrahlung) x-ray radiation with doses in the kilorad (krad(Si)) region. X-ray source targets vary in size from 2 to 25cm diameter, dependent upon the particular simulator. Electronic imaging of the source x-ray emission under dynamic conditions yields valuable information upon how the simulator is performing. The resultant images are of interest to the simulator designer who may configure new x-ray source converter targets and diode designs. The images can provide quantitative information about machine performance during radiation effects testing of components under active conditions. The effects testing program is a valuable interface for validation of high performance computer codes and models for the radiation effects community. A novel high-energy x-ray imaging spectrometer is described whereby the spectral energy (0.1 to 2.5MeV) profile may be discerned from the digitally recorded and viewable images via a pinhole/scintillator/CCD imaging system and knowledge of the filtration parameters. Unique images, analysis and a preliminary evaluation of the capability of the spectrometer are presented. Further, a novel time resolved imaging system is described that captures a sequence of high spatial resolution temporal images, with zero interframe time, in the nanosecond timeframe, of our source x-rays.

Select this Article		A new method to produce short pulses Rudolf Germer Proc. SPIE 5580, 571 (2005); http://dx.doi.org/10.1117/12.567828 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract If a coaxial cable or a strip line has an open end, then the incoming signal is reflected there. Due to the propagation velocity, an incoming rectangular pulse has a length in space which depends on its length in time. If the pulse length is twice the cable length, then after the reflection at the end, the pulse energy is distributed in an electrical field along the cable. Input and output current are compensating. At this time, it is possible to take out the energy simultanously through several switched connections at the same time. The result is a shorter pulse of much higher power which can drive a load of low impedance or with the pulse transformer presented at the 25th ICHSPP give a short pulse of very high voltage. This concentration in time of the electrical energy is planed to be used for x-ray flash systems. If the input pulse is not rectangular, then it is possible to take off the energy at the time of best peak power.Bei einem Bandleiter oder Koaxialkabel mit offenem Ende wird das auf der Leitung laufende Signal reflektiert. Die Ausdehnung eines Rechteckimpulses auf einer solchen Leitung entspricht seiner Dauer und der Ausbreitungsgeschwindigkeit auf der Leitung. Wenn die Impulsausdehnung doppelt so gross ist wie die Leitungslange, dann kann die gesamte Energie des Impulses nach der Reflexion im elektrischen Feld gespeichert sein, Eingangs und Reflexionsstrom kompensieren sich. Zu dieser Zeit ist es moglich, fast die ganze Energie gleichzeitig seitlich durch einen ausgedehnten oder mit mehreren einzelnen Schaltern an einen niederohmigen Verbraucher weiterzuleiten oder mit einem Impulstransformator ( gezeigt auf dem 25. ICHSPP ) an dessen Impedanz anzupassen. Der Ausgangsimpuls ist sehr kurz und von vervielfachter Leistung. Diese zeitliche Energiekonzentration soll spater fur Rontgenbltzsysteme verwendet werden. Im Falle eines nicht rechteckformigen Eingangsimpulses kann die Energie wahrend der hochsten Spitzenleistung entnommen werden.

Select this Article		Monochromatic flash x-ray generator utilizing copper-target diode Eiichi Sato, Michiaki Sagae, Makoto Komatsu, Rudolf Germer, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Toshio Ichimaru, Shigehiro Sato, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 579 (2005); http://dx.doi.org/10.1117/12.567585 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract High-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV using a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing the gap switches in the surge generator using a trigger device. The x-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean copper Kα lines are produced using a 10-μm-thick nickel filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. The peak tube voltage increased with increasing charging voltage. At a charging voltage of -70 kV, the peak tube voltage and current were 140 kV and 0.8 kA, respectively. The pulse widths were approximately 30 ns, and the maximum dimension of the x-ray source was 3.0 mm in diameter. The number of generator-produced Kα photons was approximately 2.5x10⁶ photons/cm² at 0.5 m per pulse.

Select this Article		Flash x-ray radiography study of the dynamic fracture of metallic discs at the interface between two colliding detonation wave fronts Kevin J. P. Reddy, Cornelis J. Terblanche, and Pieter J. Konig Proc. SPIE 5580, 586 (2005); http://dx.doi.org/10.1117/12.567051 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper the dynamic fragmentation behavior of a metal disc, positioned at the interface between colliding detonation wave fronts, is investigated. Flash x-ray radiography images from both 150kV and 450kV sytems were obtained to study the break-up phenomena of the metal disc between two similar explosive charges initiated simultaneously. The study was limited to discs of oxygen free high purity copper and an aluminium alloy (6061 T6). During the inititial shock loading phase the disc is stretched accompanied by the formation of spalling fragment rings. At a later stage discrete fragment rings are formed, which fly outward in an expanding disc fashion. The measured discrete fragment velocities ranged between 0.19 mm/μs and 2.7 mm/μs, depending on the material type. Flash x-ray radiography data at specific times is compared with numerical simulations performed using 3D-AutodynTM. Experimental techniques, procedures and results will be presented for the different metals.

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Interferometry and Imaging

Select this Article		Velocimetry using heterodyne techniques Oliver T. Strand, Leon V. Berzins, David R. Goosman, William W. Kuhlow, Paul D. Sargis, and Tony L. Whitworth Proc. SPIE 5580, 593 (2005); http://dx.doi.org/10.1117/12.567579 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract At LLNL, we have been using heterodyne techniques for the past year and a half to measure velocities up to several kilometers-per-second on different types of experiments. We assembled this diagnostic, which we call the Heterodyne Velocimeter (HetV), using commercially available products developed for the communications industry. We use a 1550 nm fiber laser and single mode fibers to deliver light to and from the target. The return Doppler-shifted light is mixed with the original laser light to generate a beat frequency proportional to the velocity. At a velocity of 1000 m/s, the beat signal has a frequency of 1.29 GHz. We record the beat signals directly onto fast digitizers. The maximum velocity is limited by the bandwidth of the electronics and the sampling rate of the digitizers. The record length is limited by the amount of memory contained in the digitizers. This paper describes our approach to measuring velocities with this technique and presents recent data obtained with the HetV.

Select this Article		Heterodyning time resolution boosting for velocimetry and reflectivity measurements David J. Erskine Proc. SPIE 5580, 600 (2005); http://dx.doi.org/10.1117/12.582723 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A theoretical technique is described for boosting the temporal resolving power by several times, of detectors such as streak cameras in experiments that measure light reflected from or transmitted through a target, including velocity interferometer (VISAR) measurements. This is a means of effectively increasing the number of resolvable time bins in a streak camera record past the limit imposed by input slit width and blur on the output phosphor screen. The illumination intensity is modulated sinusoidally at a frequency similar to the limiting time response of the detector. A heterodyning effect beats the high frequency science signal down a lower frequency beat signal, which is recorded together with the conventional science signal. Using 3 separate illuminating channels having different phases, the beat term is separated algebraically from the conventional signal. By numerically reversing the heterodyning, and combining with the ordinary signal, the science signal can be reconstructed to better effective time resolution than the detector used alone. The effective time resolution can be approximately halved for a single modulation frequency, and further decreased inversely proportional to the number of independent modulation frequencies employed.

Select this Article		Improved probe and analysis for VISAR Matthew E. Briggs, Willard F. Hemsing, Michael A. Shinas, and Gerald Whittemore Proc. SPIE 5580, 609 (2005); http://dx.doi.org/10.1117/12.584280 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We have designed and used for several years now a inch O.D., 11.5 inch length optical probe for imaging light from a surface area inside a confined space. The design is based on a commercial SelFoc gradient index objective and relay rod combination with acceptance angle +-30 degrees. We have used our probe both for framing camera images and for imaging spots on a surface onto a fiber array for interferometry. Probe efficiency is 1x10-6 at an object distance of 10 centimeters, where, for imaging onto the array, the probe has a depth of field from 2 cm to infinity. If a spot size of 1 mm is acceptable, the object can be brought within a few mm. For interferometry, the probe images enough of the surface to require automation from the analysis software. Below we report our probe construction and performance calculations, and software automation and analysis improvements.

Select this Article		Identification and removal of high-frequency temporal noise in a Nd:YAG macro-pulse laser assisted with a diagnostic streak camera Kent A. Marlett and Ke-Xun Sun Proc. SPIE 5580, 617 (2005); http://dx.doi.org/10.1117/12.567582 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper discusses the use of a reference streak camera (RSC) to diagnose laser performance and guide modifications to remove high frequency noise from Bechtel Nevada"s long-pulse laser"s output. The upgraded laser used now exhibits less than 0.1% high frequency noise in cumulative spectra, exceeding NIF calibration specifications.ICF experiments require full characterization of streak cameras over a wide range of sweep speeds (10 ns to 480 ns). This paradigm of metrology poses stringent spectral requirements on the laser source for streak camera calibration. Recently, Bechtel Nevada worked with a laser vendor to develop a high performance, multi-wavelength Nd:YAG laser to meet NIF calibration requirements. For a typical NIF streak camera with a 4096x4096 pixel CCD, flat field calibration at 30 ns requires a smooth laser spectrum over 33 MHz to 68 GHz. Streak cameras are the appropriate instrumentation for measuring laser amplitude noise at very high frequencies since the upper end spectral content is beyond the frequency response of typical optoelectronic detectors for a single shot pulse. The SC was used to measure a similar laser at its second harmonic wavelength (532 nm) establishing baseline spectra for testing signal analysis algorithms. The RSC was then used to measure the custom calibration laser. In both spatial-temporal measurements and cumulative spectra, 6~8 GHz oscillations were identified. The oscillation was diagnosed as inter-surface reflections between amplifiers. In addition, RSC spectral data changes were found due to temperature instabilities in the seeding laser. Upgrades were made on the findings and high frequency noises were removed from the laser output.

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X-Ray Sources and Applications

Select this Article		High-speed x-ray imaging in high-power laser experiments George A. Kyrala, Steve H. Batha, Jonathan B. Workman, James R. Fincke, P. A. Keiter, James A. Cobble, Nick E. Lanier, T. E. Tierney IV, and C. Christensen Proc. SPIE 5580, 629 (2005); http://dx.doi.org/10.1117/12.584782 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract X-ray imaging is one essential tool for capturing phenomena that occur when high-irradiance lasers interact with complex, optically thick targets. We use x-ray backlighting and emission to measure the result of such interactions at experiments on the Omega laser and the Z-machine z-pinch facilities. In this presentation, we will show some of the images collected with a variety of experiments, we will discuss some of the difficulties we overcame, and look to issues that will arise with higher-energy lasers and larger objects.

Select this Article		Single sub-fs XUV pulses: generation and measurement Reinhard Kienberger and Ferenc Krausz Proc. SPIE 5580, 644 (2005); http://dx.doi.org/10.1117/12.580483 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The change from a zero transition to the maximum amplitude of the electric field of visible light lasts shorter than one femtosecond (1 fs = 10^-15 s). By precisely controlling the hyperfast electric field oscillations in a short laser pulse we developed a measuring apparatus - the Atomic Transient Recorder (ATR) - like an ultrafast stopwatch. This apparatus is capable of measuring the duration of atomic processes with an accuracy of less than 100 attoseconds (1 as = 10^-18 s) which is the typical duration of electronic processes (transients) deep inside atoms. A 250 attosecond X-ray pulse initiates the atomic process to be measured and the attosecond stopwatch at the same time. This new measuring method now allows for the first time the observation of ultrafast processes in the electron shell of atoms.

Select this Article		Transient structures of crystals and liquids: an x-ray diffraction and EXAFS study Ivan V. Tomov, Jie Chen, Hua Zhang, and Peter M. Rentzepis Proc. SPIE 5580, 659 (2005); http://dx.doi.org/10.1117/12.583260 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract CBr₄ in solution was excited with 266nm picosecond pulses and the spectra and kinetics of the excited states, intermediate and final products were recorded. A long lived CBr₄ dissociation transient characterized by a broad absorption band with a maximum at 480 nm was found to be a solvent stabilized ion pair, (CBr,⁺ // Br^-)_solv. EXAFS experiments reveal the structure of CBr₄ and the final dissociation products in solution. Time resolved EXAFS studies are performed to detect and determine the structure of the dissociation intermediates as a function of time, with a resolution of a few picoseconds and 0.02 A. Transient lattice structures have been observed in metalic nano-crystals after been heated with pulsed laser excitation. The distortion of the lattice of Au (111) 150 nm thick film as a function of time after excitation has been measured.

Select this Article		Intense quasi-monochromatic flash x-ray generator utilizing molybdenum-target diode Michiaki Sagae, Eiichi Sato, Haruo Obara, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Shigehiro Sato, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 674 (2005); http://dx.doi.org/10.1117/12.581246 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the flash x-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash x rays are produced by the discharging. The x-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current were approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic x-ray intensities of molybdenum increased. The K lines were clean and intense, and hardly any bremsstrahlung rays were detected at all. The x-ray pulse widths were approximately 100 ns, and the time-integrated x-ray intensity had a value of approximately 15 μC/kg at 1.0 m from the x-ray source with a charging voltage of 80 kV.

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Applications in High-Speed Imaging III

Select this Article		Measurement system based on a high-speed camera and image processing techniques for testing of spacecraft subsystems Gianluca Casarosa and Bruno Sarti Proc. SPIE 5580, 681 (2005); http://dx.doi.org/10.1117/12.584287 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the frame of the development of new Electrical Ground Support Equipment (EGSE) for the testing phase of a spacecraft and its subsystems, the Engineering Services Section, within the Testing Division, Mechanical Systems Department, at the European Space and Technology Centre (ESTEC), has started an investigation aiming to verify the performances of a contact-less measurement system based on a high-speed camera and image processing techniques. This shall be used as an additional tool during the future test campaigns to be held at ESTEC, every time a non-intrusive GSE is required. The system is based on a Photron^TM High Speed System, composed of a High Speed camera connected to its frame-grabber via a Panel Link^TM bus, and a SW interface for the camera control.Derivative Filters and techniques for edge detection, such as the Sobel, Prewitt and Laplace algorithms, have been used for the image enhancement and processing during several tests campaigns, which have been held to evaluate the measurement system. The improvement of the detection of the movement of the specimen has been achieved by sticking, where possible, one or more optical targets over the surface of the test article. The targets are of two types: for ambient and vacuum qualified.The performances of the measuring system have been evaluated and are summarized in this paper. The limitations of the proposed tool have been assessed, together with the identifications of the possible scenarios where this system would be useful and could be applied to increase the effectiveness of the verification phase of a spacecraft-subsystem.

Select this Article		A low-cost time-resolved spot diagnostic for flash x-ray machines J. Howorth, Martin B. Ingle, Peter Simpson, Christopher Aedy, and Stephen Quillin Proc. SPIE 5580, 693 (2005); http://dx.doi.org/10.1117/12.584620 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract AWE has embarked on a programme to develop an improved intense electron beam diode for flash x-ray radiography machines. In order to understand the performance of the diode and to validate computer modelling codes, there is a requirement to obtain time resolved x-ray spot size and position data during the 50 ns electron beam pulse.A simple, low cost, time resolved spot diagnostic has been designed in collaboration with Photek Limited. The system is based around number of identical, single frame, fast gating intensified CCD camera modules viewing a very fast organic scintillator. Each camera has an independent internal delay generator and a microchannel plate intensifier (MCP) capable of gate widths down to 1 ns. The complete system is battery driven and controlled remotely via optical fibres to provide electrical isolation and reduce Electro Magnetic Interference (EMI) susceptibility.An initial four frame system (easily extendable to 8 frames and beyond) has been developed and deployed successfully on one of AWE"s flash x-ray machines.

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Poster Session

Select this Article		Klystron-type photoelectron gun design for femtosecond electron diffractometer Alexander M. Tron and Igor G. Merinov Proc. SPIE 5580, 700 (2005); http://dx.doi.org/10.1117/12.567187 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Axisymmetric self-consistent dynamics of femtosecond electron bunches in a klystron-type photoelectron gun for a time-resolved electron diffractometer is investigated. The proposed gun consists from a planar gap modulating the bunch and the following units: lens, target-sample (exited by a laser pulse) and screen, placed in series downstream. The gap, restricted by photocathode and anode containing the bunch transit hole or a mesh, accelerates and modulates the photoelectrons of the bunch in longitudinal velocity. The target is placed in the longitudinal focus of the gap, the focus of which is after and in a rather far distance from the lens focusing the photoelectrons on the screen. The optimized magnitudes of the bunch population and the other parameters of the gun are determined from the terms of getting the longitudinal focus length of about 100 mm and the bunch duration, its energy spread of the order of 100 fs and 1 eV, respectively, at the point of this focus. The results of the bunch dynamics simulation for the bunch population of 105-104 photoelectrons, the initial bunch duration of 500 fs and at consideration of the initial bunch radius not more 0.5 mm and the initial energy spread from 0 to 0.5 eV are presented and discussed.

Select this Article		On the theory of temporal aberrations for electron optical imaging systems by using direct integral method Liwei Zhou, Yuan Li, Zhiquan Zhang, Mikhail A. Monastyrskiy, and Mikhail Y. Schelev Proc. SPIE 5580, 710 (2005); http://dx.doi.org/10.1117/12.567688 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A new approach to the theory of temporal aberration for the dynamic electron optical imaging systems is given in the present paper. A new definition of temporal aberrations is given in which a certain initial energy of electron emission along the axial direction ϵ_z1(0≤ϵ_z1≤ϵ_0max) is considered. A new method to calculate the temporal aberration coefficients of dynamic electron optical imaging system, which is named "Direct Integral Method", is also presented. All of the formulae of the temporal aberration coefficients deduced from "Direct Integral Method" and "-Variation Method" have been verified by an electrostatic concentric spherical system model, and contrasted with the analytical solutions. Results show that these two methods have got identical solution and the solutions of temporal aberration coefficients of first and second-order are the same with the analytical solutions. Thus it can be concluded these two methods given by us are equivalent and correct, but the "Direct Integral Method" is related to solve integral expressions, which is more convenient for computation and could be suggested to use in the practical design.

Select this Article		Multibeam cross-correlation method of measurement of spectral and temporal characteristics of femtosecond laser pulses Alexander O. Vardanyan Proc. SPIE 5580, 725 (2005); http://dx.doi.org/10.1117/12.567334 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The indirect measurement method of the temporal profile and spectrum of Femtosecond Laser Pulses (FLP) carried out by the multi-beam cross-correlator is described. The method of temporal scaling of the single-shot irreproducible FLP under investigation was applied by scanning of the broadened FLP spectrum by pulses of a given shape at various wavelengths in a non-linear crystal. As a result of such an interaction a dynamic spectrogram is formed at the output of the non-linear crystal, from which the temporal profile and spectrum of the investigating FLP is defined.

Select this Article		Picosecond time response characteristics of microchannel plate PMT detectors James S. Milnes and J. Howorth Proc. SPIE 5580, 730 (2005); http://dx.doi.org/10.1117/12.568180 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The output pulse width in the time response of photo-multiplier tubes (PMT) is much faster in micro-channel plate (MCP) models compared to more standard dynode chain PMTs due to a vastly reduced variation in the path length of the electrons through the amplifying system. Typically the pulse widths can be in the region of 200ps compared to the nanosecond domain occupied by the best conventional PMTs. Photek manufacture PMTs with one, two or three MCPs depending on the gain required, and also use the same structure without any MCPs to work as simple photodiodes. We demonstrate the variation of output pulse characteristics due to the number and design of MCPs in a range of PMT models and illustrate the importance of having a properly designed 50ohm transmission line to deliver the pulse from the detector.

Select this Article		CMOS sensor for face tracking and recognition Dominique Ginhac, Eri Prasetyo, and Michel Paindavoine Proc. SPIE 5580, 741 (2005); http://dx.doi.org/10.1117/12.570409 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper describes the main principles of a vision sensor dedicated to the detecting and tracking faces in video sequences. For this purpose, a current mode CMOS active sensor has been designed using an array of pixels that are amplified by using current mirrors of column amplifier. This circuit is simulated using Mentor Graphics software with parameters of a 0.6 μm CMOS process. The circuit design is added with a sequential control unit which purpose is to realise capture of subwindows at any location and any size in the whole image.

Select this Article		Influence of internal geometric configuration of soft flash x-ray tube in radiation dosage Makoto Komatsu, Eiichi Sato, Hidenori Ojima, and Kazuyoshi Takayama Proc. SPIE 5580, 750 (2005); http://dx.doi.org/10.1117/12.567273 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In previous experiment, some papers reported that circular truncated shape can make suitable radiation output for radiography in comparison with cylinder target. Therefore, we carried out experiments to confirm the influence of the tip shape of the titanium target in the radiation dose using the x-ray tube, which have used by former experiment. It visualized an x-ray source using the Computed Radiography (CR) system and it measured the spatial distribution of the radiation dose relatively. At the same time, tube voltage and current was measured by high-voltage divider and current transformer, respectively. Prepared target shapes are cylinder and circular truncated cone. As the result, in this experiment, a beam spot was seen only with the tip of the target. Moreover, radiation dosage is influenced in distance between target and graphite cathode, rather than in shape of the target. In present study, we did not clearly recognize improvement of x-ray output dosage by using circular truncated cone target as before.

Select this Article		Irradiation of orderly multiline spectra from linear plasma formed by vacuum discharge capillary Eiichi Sato, Yasuomi Hayasi, Rudolf Germer, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 758 (2005); http://dx.doi.org/10.1117/12.568980 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments are primarily performed in order to generate intense soft x rays. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbomolecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -11.5 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 μm aluminum filter were less than 30 μs. In the spectrum measurement, we observed orderly multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. The line number decreased with corresponding decreases in the capillary length.

Select this Article		Energy-selective high-speed radiography utilizing stroboscopic x-ray generator Eiichi Sato, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Shigehiro Sato, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 765 (2005); http://dx.doi.org/10.1117/12.568959 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Energy-selective high-speed radiography utilizing a kilohertz-range stroboscopic x-ray generator and its application to high-speed angiography are described. This generator consists of the following major components: a main controller, a condenser unit with a Cockcroft-Walton circuit, and an x-ray tube unit in conjunction with a grid controller. The main condenser of about 500 nF in the unit is charged up to 100 kV by the circuit, and the electric charges in the condenser are discharged to the triode by the grid control circuit. Although the tube voltage decreased during the discharging for generating x rays, the maximum value was equal to the initial charging voltage of the main condenser. The maximum tube current and the repetition rate were approximately 0.5 A and 32 kHz, respectively. The x-ray pulse width ranged from 0.01 to 1.0 ms, and the maximum shot number had a value of 32. At a charging voltage of 80 kV and a width of 1.0 ms, the x-ray intensities obtained without filtering, using an aluminum filter, and using a barium sulfate filter were 14.8, 5.48 and 5.05 μGy per pulse, respectively, at 1.0 m, and the dimensions of the focal spot had values of 3.5×3.5 mm. Angiography was performed using both the aluminum and the barium sulfate filters at a charging voltage of 60 kV.

Select this Article		ICAM: a smart camera for very high-speed processing Barthelemy Heyrman, Michel Paindavoine, and Renaud Schmit Proc. SPIE 5580, 772 (2005); http://dx.doi.org/10.1117/12.573516 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Computer assisted-vision plays a greater and greater part in our society, in various fields such as people and goods safety, industrial production, telecommunications, robotic... However, technical developments are still timid and slowed down by various factors linked to the sensors cost, to the systems lack of flexibility, to the difficulty of developing rapidly complex and robust applications, and to the lack of interaction among these systems themselves, or with their environment. This paper describes the ICAM(Intellignent CAMera) project, a smart camera with real-time video processing capabilities. This camera associates a sensor with massively parallel outputs and a SIMD processors network to achieve very high speed processing. The paper presents the first modelisation of this device and first results.

Select this Article		A CMOS image sensor dedicated to medical gamma camera application Nur S. Salahuddin, Michel Paindavoine, Dominique Ginhac, Michel Parmentier, and Najia Tamda Proc. SPIE 5580, 778 (2005); http://dx.doi.org/10.1117/12.577845 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Generally, medical Gamma Camera are based on the Anger principle. These cameras use a scintillator block coupled to a bulky array of photomultiplier tube (PMT). To simplify this, we designed a new integrated CMOS image sensor in order to replace bulky PMT photodetetors. We studied several photodiodes sensors including current mirror amplifiers. These photodiodes have been fabricated using a CMOS 0.6 micrometers process from Austria Mikro Systeme (AMS). Each sensor pixel in the array occupies respectively, 1mm x 1mm area, 0.5mm x 0.5mm area and 0.2mm 0.2mm area with fill factor 98 % and total chip area is 2 square millimeters. The sensor pixels show a logarithmic response in illumination and are capable of detecting very low green light emitting diode (less than 0.5 lux) . These results allow to use our sensor in new Gamma Camera solid-state concept.

Select this Article		Image intensified cameras for high-speed imaging applications that require more than just the high frame-rate Thomas F. Lynch and Anjie Zeng Proc. SPIE 5580, 790 (2005); http://dx.doi.org/10.1117/12.562303 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The nature of high-speed or high frame rate imaging results in a short exposure time requiring the object be illuminated with a high brightness light source. In some cases, as in biological studies and other heat sensitive materials this is not an option. For these low light level applications we have developed an intensified high-speed camera. This camera extends the sensitivity to 10^-6 fc (10^-5 lux) at a minimum frame rate of 1000 frames per second (fps). Frame rates well above 1000 fps have been achieved. Part of the success of this camera lies in the use of a high quantum efficiency (QE) image intensifier, having a GaAs photocathode with a QE exceeding 50%, fiber optically coupled to a high-speed camera. The intensifier, which can be gated, also serves as an external shutter to the image sensor. The gate allows exposures as short as 50 ns not achievable with the unintensified camera. The gate can be delayed and synced with the image to capture information at the right moment. Gating also allows the camera to be used in brighter situations extending the dynamic range of the camera to over 10 orders of magnitude.

Select this Article		An image sensor of 1,000,000 fps, 300,000 pixels, and 144 consecutive frames Takeharu G. Etoh, Yuya Hatsuki, Tomoo Okinaka, Hiroshi Ohtake, Hirotaka Maruyama, Tetsuya Hayashida, Masato Yamada, Kazuya Kitamura, Toshiki Arai, Kenkichi Tanioka, Dirk Poggemann, Arno Ruckelshausen, Harry van Kuijk, Jan T. Bosiers, and Albert J. Theuwissen Proc. SPIE 5580, 796 (2005); http://dx.doi.org/10.1117/12.566156 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract An image sensor for an ultra-high-speed video camera was developed. The maximum frame rate, the pixel count and the number of consecutive frames are 1,000,000 fps, 720 x 410 (= 295,200) pixels, and 144 frames. A micro lens array will be attached on the chip, which increases the fill factor to about 50%. In addition to the ultra-high-speed image capturing operation to store image signals in the in-situ storage area adjacent to each pixel, standard parallel readout operation at 1,000 fps for full frame readout is also introduced with sixteen readout taps, for which the image signals are transferred to and stored in a storage device with a large capacity equipped outside the sensor. The aspect ratio of the frame is about 16 : 9, which is equal to that of the HDTV format. Therefore, a video camera with four sensors of the ISIS-V4, which are arranged to form the Bayer"s color filter array, realizes an ultra-high-speed video camera of a semi-HDTV format.

Select this Article		Studies on degree of freedom for high-speed photography Jingzhen Li, Xianxiang Tan, Xiangdong Gong, and Yuexia Ai Proc. SPIE 5580, 805 (2005); http://dx.doi.org/10.1117/12.569012 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In this paper we try to perfect information theory of high speed photography (HSP), which are theoretically and practically analyzed with theory on degree of freedom (DOF). Generally speaking, information theory of HSP should be able to used for evaluating HSP systems and HSP methods, and for the best it should be able to show the way to upgrade HSP's performances and throughly exploits resources of the recording light used as information carrier. As a method for studying information theory of HSP, optical DOF theory should be utilized at first, in which particularities of HSP systems, statistical rules of measured events and know-how from long-term HSP"s practices must be taken into consideration.

Select this Article		Streak camera diagnostic of femtosecond laser spark Sergei V. Garnov, Vitali I. Konov, V. I. Lozovoi, Alexander A. Malyutin, Mikhail Y. Schelev, and Nikolai S. Vorobiev Proc. SPIE 5580, 811 (2005); http://dx.doi.org/10.1117/12.571805 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We report on time-resolved spectroscopy of femtosecond laser plasma with the use of ultrafast streak cameras. Laser spark was excited in air, nitrogen, argon or helium by tightly focused Ti: sapphire 130 fs, 1mJ, 800 nm single laser pulses. Maximum laser radiation intensity in the focal point was up to 2.5x10¹⁷ W/cm². The time behavior of laser plasma continuum, tabulated spectral lines as well as the second and third harmonics were observed with pico-femtosecond time resolution. We believe that the second harmonic generation in femtosecond laser spark was recorded for the first time.

Select this Article		Demonstration of flash K-edge angiography utilizing gadolinium-based contrast medium Eiichi Sato, Michiaki Sagae, Haruo Obara, Rudolf Germer, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Toshio Ichimaru, Shigehiro Sato, Hidenori Ojima, Kazuhiro Takayama, and Hideaki Ido Proc. SPIE 5580, 817 (2005); http://dx.doi.org/10.1117/12.581179 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Tungsten characteristic x rays can be produced, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 140 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 90 ns, and the estimated number of K photons was approximately 5×10⁸ photons/cm² per pulse at 0.5 m from the source of 3.0 mm in diameter.

Select this Article		Superposition of x-ray spectra using double-target plasma triode Haruo Obara, Eiichi Sato, Etsuro Tanaka, Hidezo Mori, Toshiaki Kawai, Shigehiro Sato, Hidenori Ojima, Kazuyoshi Takayama, and Hideaki Ido Proc. SPIE 5580, 824 (2005); http://dx.doi.org/10.1117/12.581235 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the plasma flash x-ray generator, a 200 nF condenser is charged up to 50 kV by a power supply, and flash x rays are produced by the discharging. The x-ray tube is a demountable triode with a double target consisting of a copper and a molybdenum rods, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Target evaporation leads to the formation of weakly ionized linear plasma, consisting of metal ions and electrons, around the fine target, and intense characteristic x rays are produced. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 11 kA. When the charging voltage was increased, the linear plasma formed, and the molybdenum K-series characteristic x-ray intensities increased substantially. Although the intensities of copper Kα lines increased with increases in the charging voltage, hardly any clean Kα lines were detected. The x-ray pulse widths were approximately 1.2 μs, and the time-integrated x-ray intensity was approximately 30 μC/kg at 1.0 m from the x-ray source with a charging voltage of 50 kV.

Select this Article		Instantaneous temperature visualization of a turbulent flame using multidirectional interferometer Junta Doi and Seishiro Sato Proc. SPIE 5580, 832 (2005); http://dx.doi.org/10.1117/12.583299 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We have reconstructed a three-dimensional instantaneous temperature distribution inside a turbulent flame of a propane-air premixed burner using multidirectional holographic interferograms and visualized by constructing a geometric model of the three-dimensional isothermal surfaces. To reconstruct a three-dimensional asymmetric temperature field, the interference fringe data were acquired using an eight-directional Twyman-Green interferometer, over a full range of viewing angles, around the object flame, and all data are simultaneously acquired. A ruby laser, having a beam with a 20-30 ns pulse width, was used to obtain clear fringe patterns for this type of turbulent phenomena. The temperature distribution was reconstructed from the refractive index distribution, obtained from the fringe patterns, based on a computed tomography technique of a convolution reconstruction algorithm. Isothermal profiles were calculated in horizontal cross sections from the temperature data. All of the multiple isothermal contour lines in each horizontal section were approximated with polygons and then stacked up vertically to form polyhedra of the solid model format, having side facets of corresponding isothermal values. Computer graphics of the solid models, not only of the initial isothermal solids, but also of the solids resulting from multiple Boolean operations on them, were used to show the distribution in detail. This development will be of help in studying the local structure of the instantaneous turbulent flame and in integrating the experimental modeling with the numerical simulation.

Select this Article		Evaluation of digital flash x-ray images produced using computed radiography Torgny E. Carlsson and Hakan Ornhed Proc. SPIE 5580, 842 (2005); http://dx.doi.org/10.1117/12.584179 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Methodologies to extract information from flash X-ray images produced using Computed Radiography (CR) are described. In this process, the exposed image plate is directly and accurately scanned by a laser beam into digital format. Compared with photographic X-ray recordings, better geometrical stability and higher contrast are achieved. This enables more elaborate image and signal processing techniques to be applied to the images, resulting in a higher capacity to extract information from the recordings. Here, the density and velocity profiles along non-particulated shaped charge jets from flash radiography imaging have been evaluated. The mass distribution was estimated using the Abel transform, where the contrast to density calibration was done directly from information extracted from the images. The velocity evaluation was performed in two steps. The sums of intensities along cross sections were evaluated using image processing. By assuming constant jet density and identifying corresponding parts of the curves, the velocity profile along the jet is evaluated.

Select this Article		High-speed hyperspectral measurement of sprites Matthew G. McHarg Proc. SPIE 5580, 851 (2005); http://dx.doi.org/10.1117/12.584299 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We describe a hyper-spectral measurement technique for sprite observations which takes data at 25,000 samples per second in 32 individual color bands. The high speed hyper-spectral design is based around a 32 channel multi anode photometer (MAP) viewing a dispersing grating which is holographically inscribed on a spherical focusing mirror. Design and operating characteristics of the device are presented. The high speed hyper-spectral instrument will be used to observe spectra from transient luminous events called sprites seen above meso-scale thunderstorms. Sprites are seen to occur at altitudes of 40-90 km, and last a few to tens of milliseconds in duration. High speed spectral measurements may give some indication of the energetic processes underlying sprite formation. We are particularly interested in the overall energy budget associated with sprites in large meso-scale thunderstorm complexes.

Select this Article		Implementing techniques of holography-based multiframe extreme high-speed photography Jingzhen Li, Xiangdong Gong, Shanxiang Li, and Yuexia Ai Proc. SPIE 5580, 860 (2005); http://dx.doi.org/10.1117/12.568768 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract A key to implement tubeless extreme high speed photography (EHSP) is to ask for help from parallel processing of light and to exploit different light properties: amplitude, phase, polarization, wavelength, wave vector, even photon spin and photon mode. Holography is an important technique to implement multi-frame EHSP, because a hologram is a result derived from contributions of multiple light merits. In this paper, techniques to implement holography-based EHSP are described, including mechanism of generating multiple frames and extreme high photographic rate.

Select this Article		Diagnostics for confined plasma ablation for plate launch and shock generation Dennis L. Paisley, D. C. Swift, T. E. Tierney IV, C. P. Munson, and R. P. Johnson Proc. SPIE 5580, 868 (2005); http://dx.doi.org/10.1117/12.592188 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Confined plasma ablation is an efficient method to accelerate 1-D metal plates, with the impact of the plate resulting in a well-defined shock being generated in a target material. By using confined plasma to accelerate a plate, some details of the laser parameters are decoupled from the plate impact. Several types of experiments and related diagnostics to evaluate the performance parameters of the laser beam, flyer plate acceleration, and plate conditions are described. Several experiments using the flyer plates to generate shocks in materials to determine pressure-velocity relations, and dynamic spall strength of various metals are presented.

Select this Article		Development of a high-speed CMOS drum camera with multiple focal depths Makoto Komatsu, Tsutomu Saito, Eiichi Sato, Kazuyoshi Takayama, Toshio Hukui, Teiichi Ohkouchi, Eiji Ishikawa, Akira Suzuki, Nobuie Konishi, Kenji Mitsui, Shiro Shibasaki, and Koji Shibasaki Proc. SPIE 5580, 873 (2005); http://dx.doi.org/10.1117/12.578649 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract We experimentally made the high-speed drum camera which had the motor of 80,000 rounds per minute (rpm) at rotating mirror on object beam. This paper describes results of the experiments about its basic optics, the subjects in the future and plans for improvement of the performance. The experimental monochromatic CCD image showed that the optical system employed in present study is proper basically. Additionally, this camera enable to the high-speed photography at about 520,000 frames per second, and we could show the specific policy to realize 1,000,000 frames per second in the near future.

Select this Article		Application of K008 camera within measuring complex of laser diagnostics of shock and detonation waves Vitaly B. Lebedev, Grigory G. Feldman, Maxim A. Karpov, Alexey V. Fedorov, Alexey V. Menshikh, Dmitriy V. Nazarov, Stanislav A. Finyushin, and Valeriy A. Davidov Proc. SPIE 5580, 881 (2005); http://dx.doi.org/10.1117/12.597445 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract In May 2001 the K008 camera/1,2/ being a part of a laser Doppler velocity meter (LDVM) experimental complex of the Russion Federation Nuclear Center, the All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF), was tested under real conditions of gas-dynamic experiments. Some tasks typical to explosion physics were solved during these experiments: the record of velocities of the plates thrown by an explosion; the record of shock and detonation wave fronts; the record of elastic-plastic properties of constructional materials. At the same time the following camera's characterstics were checke: resistance to electromagnetic, acoustic and light interference; conformity of real characteristics to Documentation data; convenience in operation and reliability.

Select this Article		Features of application of image converter cameras for research on lightning and discharges in long air gaps Vitaly B. Lebedev, Grigory G. Feldman, Boris N. Gorin, Yuri V. Shcherbacov, Vladimir S. Syssoev, and Vladimir A. Rakov Proc. SPIE 5580, 887 (2005); http://dx.doi.org/10.1117/12.597448 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The present report generalizes materials of publication /1-3/. In doing so /1/ and /3/ were presented at appropriate symposiums only as poster reports and were not widely discussed.Creation of reliable physical and engineering models of sequence of leader-return stroke of lightning (L-RS) and an attachment process is hampered by lack of actual information on the optical picture of low-luminous streamer structures of lightning. Cameras based on an image converter tubes (ICT) /4/ serve as an alternative of traditional optical-mechanical means for recording a lightning image. Such cameras allowed to obtain new reults when investigating streamer processes of a long spark what made it possible to formulate a set of hypothesizes relating to a leader process of lightning /5-7/.Here there are given the characteristics of the image converter instrumentation complex adapted to the work with lightning and a long spark and there are presented the results of its tests in the All-Russian Electro-technical Institute (VEI) named after V.I. Lenin when recording a long spark on the open high-voltage stand in Istra (near Moscow).

Select this Article		Application of the K008 camera in nonstationary spectroscopy Vitaly B. Lebedev, Grigory G. Feldman, Andrey B. Savel'ev, Ignac Bugar, and Dusan Chorvat, Jr. Proc. SPIE 5580, 898 (2005); http://dx.doi.org/10.1117/12.597451 \| Cited 1 time Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract Since August 2003 the K008 camera /1,2/ being coupled with a MS 3504i monochromator/spectrogaph /3/ has been used in the International Laser Center in Bratislava (Slovak Republic) for investigations in the field of non-stationary spectroscopy, in particular, for the study of fluorescence processes in different dyes. When putting the camera into operation its limiting temporal resolution was prelinarily checked and was found to be 20ps. The results of trial experiments on the study of dynamics of Rhodamin B fluorescence are given below.

Select this Article		New ultrahigh-speed CCD camera achieves sub-electron read noise using on-chip multiplication gain (EMCCD) technology Ravi K. Guntupalli, Vern Hagan, Andrew Cooper, and Raymond W. Simpson Proc. SPIE 5580, 905 (2005); http://dx.doi.org/10.1117/12.602558 Online Publication Date: Mar 25, 2005 Full Text: \| Download PDF
	+ -	Show Abstract The imaging performance of a high speed camera utilizing novel "on-chip electron multiplication gain CCD (EMCCD)" technology is presented. The EMCCD technology has become a popular choice for low-light, high-speed scientific imaging and spectroscopy applications. By amplifying the signal right on the CCD, the new technology overcomes the read noise limitation, typical of high speed CCD cameras. Using all solid-state technology, the EMCCDs alleviate the shortcomings of the traditional amplification technologies using external photocathode materials such as intensified CCD (ICCD) and electron-bombarded CCD (EBCCD) cameras. For example, the technology is not susceptible to burn-in or damage in high light conditions and does not suffer from potential loss of spatial resolution in the photocathode material. A new camera, Cascade:128+, was developed using back illuminated, frame transfer EMCCD with 128x128 pixels to achieve frame rates in excess of 510 full frames per second and the system read noise below one electron rms. Custom data acquisition hardware and software allow real time access to the image data. The camera is ideal for high-frame rate, low-light level imaging applications in physical and biological sciences including adaptive optics, plasma diagnostics, neural-imaging and single molecule tracking.

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