We report on the upgraded One Degree Imager (ODI) at the WIYN 3.5 meter telescope at the Kitt Peak Observatory after the focal plane was expanded by an additional seventeen detectors in spring 2015. The now thirty Orthogonal Transfer Array CCD detectors provide a total field of view of 40’ x 48’ on the sky. The newly added detectors underwent a design revision to mitigate reduced charge transfer efficiency under low light conditions. We discuss the performance of the focal plane and challenges in the photometric calibration of the wide field of view, helped by the addition of telescope baffles. In a parallel project, we upgraded the instrument’s three filter arm mechanisms, where a degrading worm-gear mechanism was replaced by a chain drive that is operating faster and with high reliability. Three more filters, a u’ band and two narrow band filters were added to the instrument’s complement, with two additional narrow band filters currently in procurement (including an Hα filter). We review the lessons learned during nearly three years of operating the instrument in the observatory environment and discuss infrastructure upgrades that were driven by ODI’s needs.
KEYWORDS: Servomechanisms, Optical instrument design, Control systems, Telescopes, Control systems design, Computer programming, Space telescopes, Mirrors, Observatories
Motivated by a desire to improve the KPNO Mayall 4m telescope’s pointing and tracking performance prior to the start of the DESI installation and by a need to improve the maintainability of its telescope control system (TCS), we recently completed a major modernization of that system based heavily on recent changes made at the CTIO Blanco 4m, as described by Warner et al (2012). We describe here the things we did differently from the Blanco upgrade. We also present results from the as-built performance of the new servo and pointing systems.
We describe the design, construction and measured performance of the Kitt Peak Ohio State Multi-Object Spectrograph
(KOSMOS) for the 4-m Mayall telescope and the Cerro Tololo Ohio State Multi-Object Spectrograph (COSMOS) for
the 4-m Blanco telescope. These nearly identical imaging spectrographs are modified versions of the OSMOS
instrument; they provide a pair of new, high-efficiency instruments to the NOAO user community. KOSMOS and
COSMOS may be used for imaging, long-slit, and multi-slit spectroscopy over a 100 square arcminute field of view with
a pixel scale of 0.29 arcseconds. Each contains two VPH grisms that provide R~2500 with a one arcsecond slit and their
wavelengths of peak diffraction efficiency are approximately 510nm and 750nm. Both may also be used with either a
thin, blue-optimized CCD from e2v or a thick, fully depleted, red-optimized CCD from LBNL. These instruments were
developed in response to the ReSTAR process. KOSMOS was commissioned in 2013B and COSMOS was
commissioned in 2014A.
Early detection of ovarian cancer could greatly increase the likelihood of successful treatment. However, present detection techniques are not very effective, and symptoms are more commonly seen in later stage disease. Amino acids, structural proteins, and enzymatic cofactors have endogenous optical properties influenced by precancerous changes and tumor growth. We present the technical details of an optical spectroscopy system used to quantify these properties. A fiber optic probe excites the surface epithelium (origin of 90% of cases) over 270 to 580 nm and collects fluorescence and reflectance at 300 to 800 nm with four or greater orders of magnitude instrument to background suppression. Up to four sites per ovary are investigated on patients giving consent to oophorectomy and the system's in vivo optical evaluation. Data acquisition is completed within 20 s per site. We illustrate design, selection, and development of the components used in the system. Concerns relating to clinical use, performance, calibration, and quality control are addressed. In the future, spectroscopic data will be compared with histological biopsies from the corresponding tissue sites. If proven effective, this technique can be useful in screening women at high risk of developing ovarian cancer to determine whether oophorectomy is necessary.
As astronomical instruments have increased in complexity, cost and production time, sharing a major instrument
between telescopes has become an attractive alternative to duplication. This requires solving technical and logistical
problems of transportation, transferring operational support knowledge between on-site staffs, and developing effective
responses to in-service problems at a different site. The infrared camera NEWFIRM has been operated for two years on
the 4-m Mayall telescope of Kitt Peak National Observatory in Arizona. We have recently temporarily moved it to the 4-
m Blanco telescope of Cerro Tololo Interamerican Observatory in Chile for a limited period of operation. We describe
here our solutions to the challenges involved in relocating this major in-service cryogenic instrument, with an emphasis
on "lessons learned" to date.
KEYWORDS: Sensors, Charge-coupled devices, Power supplies, Analog electronics, Signal detection, Control systems, Electronics, Clocks, Detector development, Calibration
The Torrent detector control system is being developed at NOAO as a follow-on to the MONSOON systems that
have been used successfully for instruments at several institutions. The poster will cover the evolution of
MONSOON into Torrent and will cover: Motivations, What's gained/What's lost, Major Technological Differences,
Goals, plans and first users.
KEYWORDS: Sensors, Control systems, Calibration, Field programmable gate arrays, Signal detection, Analog electronics, Mirrors, Clocks, Connectors, Power supplies
The MONSOON Torrent image Acquisition system is being designed partially to reduce the complexity in
configuring a Detector controller system. This paper will discuss how we have achieved this goal by creating a system
of automation for the configuration task. We also discuss how the automated systems work to insure proper focal plane
operation in the face of potential network, communications and controller hardware failures during observing sessions.
The Torrent hardware design is discussed in section 2. In Sections 4 and 5 we discuss the automated processes used
to develop the description of the Torrent hardware used by the rest of the automation system. In Sections 6 through 8 we
discuss the semi automated system configuration/integration/design software. In Section 9 we present the automated
run-time configuration tools and discuss how it operates in the face of various failures. In Section 10 we discuss how
Torrent and the automated systems will achieve the goal of reducing observing down time in the face of hardware
failures.
NEWFIRM, the widefield infrared camera for the NOAO 4-m telescopes, saw first light in February 2007 and is now in
service as a general user instrument. Previous papers have described it conceptually and presented design details. We
discuss experience gained from assembly, laboratory testing, and on-sky commissioning. We present final system
performance characteristics and summarize science use in its the first semester of general availability. NEWFIRM has
met its requirement to provide a high efficiency observing system, optimized end-to-end for survey science.
The Gemini Near-Infrared Spectrograph (GNIRS) supports a variety of observing modes over the 1-5 μm wavelength
region, matched to the infrared-optimized performance of the Gemini 8-m telescopes. We describe the optical,
mechanical, and thermal design of the instrument, with an emphasis on challenging design requirements and how they
were met. We also discuss the integration and test procedures used.
A transmission-line model of a two-stage all-fiber soliton-effect femtosecond-pulse compressor is designed using comprehensive simulation tools. The compressor is predicted to have compression factors as high as 24, with low peak power (<0.5 nJ pulse energy at a 180-fs pulse width) and high repetition rate (~40 GHz) without many of the disadvantages of heretofore-designed compressors. Prior optical pulse compressors are primarily based on solid state lasers or fiber Bragg gratings. Solid state lasers are relatively large, have high pulse energies (~10 nJ), and lack the precision needed for many applications, such as in medical diagnosis and treatment. Fiber Bragg grating compressors are limited in attainable compression factors and intensity levels and have restricted use with other fiber Bragg gratings. Other fiber compressors face third-order dispersion (TOD), self-steepening (SS), intrapulse stimulated Raman scattering (ISRS), and higher order dispersion (HOD), which limits their use. The suggested design addresses a requirement for the modeling of an all-fiber optical pulse compressor that answers the preceding objections. The designed compressor, has no third-order or higher order dispersion, and is not affected by ISRS and SS effects, which can otherwise reduce the quality of the compressed pulses.
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