Dr. Jungki Song Profile

Dr. Jungki Song

Graduate Student at Massachusetts Institute of Technology

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Author

Publications (9)

Proceedings Article | 23 August 2021 Presentation + Paper

Manufacture and performance of blazed soft x-ray transmission gratings for Arcus and Lynx

Ralf Heilmann, Alexander Bruccoleri, Jungki Song, Bethany Levenson, Brian Smallshaw, Mallory Whalen, Alan Garner, Sarah Trowbridge Heine, Herman Marshall, Matthew Cook, James Gregory, Renee Lambert, Dmitri Shapiro, Douglas Young, Eric Gullikson, Tomoyuki Nonaka, Akimi Uchida, Manuel Quijada, Ed Hertz, Peter Cheimets, Randall Smith, Mark Schattenburg

Proceedings Volume 11822, 1182215 (2021) https://doi.org/10.1117/12.2594951

KEYWORDS: Diffraction gratings, Computed tomography, Semiconducting wafers, X-rays, Diffraction, Etching, Deep reactive ion etching, Photomasks, Optical alignment, X-ray diffraction

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Proceedings Article | 13 December 2020 Presentation + Paper

Towards volume manufacturing of high-performance soft x-ray critical-angle transmission gratings

Ralf Heilmann, Alexander Bruccoleri, Jungki Song, Matthew Cook, James Gregory, Renee Lambert, Dimitri Shapiro, Douglas Young, Miranda Bradshaw, Vadim Burwitz, Gisela Hartner, Andreas Langmeier, Randall Smith, Mark Schattenburg

Proceedings Volume 11444, 114441H (2020) https://doi.org/10.1117/12.2562388

KEYWORDS: Diffraction gratings, X-rays, Manufacturing, Spectroscopy, Computed tomography, Diffraction, Absorption, Emission spectroscopy, Diagnostics, Plasmas

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Proceedings Article | 13 December 2020 Presentation + Paper

CAT grating alignment and testing for soft x-ray polarimetry

Alan Garner, Herman Marshall, Sarah Trowbridge Heine, Ralf Heilmann, Jungki Song, Norbert Schulz, Beverly LaMarr, Mark Egan

Proceedings Volume 11444, 114445Z (2020) https://doi.org/10.1117/12.2561734

KEYWORDS: Polarimetry, X-rays, Computed tomography, Optical alignment, Rockets, Monochromators, Prototyping, Crystals

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Proceedings Article | 9 September 2019 Paper

Component testing for x-ray spectroscopy and polarimetry

Alan Garner, Herman Marshall, Sarah Trowbridge Heine, Ralf Heilmann, Jungki Song, Norbert Schulz, Beverly LaMarr, Mark Egan

Proceedings Volume 11118, 1111811 (2019) https://doi.org/10.1117/12.2529607

KEYWORDS: X-rays, Polarimetry, Spectroscopy, Rockets, Optical design, Monochromators, Polarization

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Proceedings Article | 9 September 2019 Paper

Progress in x-ray critical-angle transmission grating technology development

Ralf Heilmann, Alexander Bruccoleri, Jungki Song, Mark Schattenburg

Proceedings Volume 11119, 1111913 (2019) https://doi.org/10.1117/12.2529354

KEYWORDS: X-rays, Diffraction gratings, X-ray technology, Computed tomography, Spectroscopy, Diffraction, Spectral resolution, Galaxy groups and clusters, Stars, Tolerancing

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Proceedings Article | 6 July 2018 Presentation + Paper

Metrology for quality control and alignment of CAT grating spectrometers

Jungki Song, Ralf Heilmann, Alexander Bruccoleri, Edward Hertz, Mark Schattenburg

Proceedings Volume 10699, 106990S (2018) https://doi.org/10.1117/12.2314902

KEYWORDS: Diffraction gratings, Metrology, X-rays, Optical alignment, Diffraction, Spectrometers, Deep reactive ion etching

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Arcus, a mission proposed as a Medium Size Explorer for high-resolution x-ray spectroscopy, requires unprecedented sensitivities: high resolving power (λ/Δλ >; 2500) and large collecting area (~ 350 cm²). The core instruments on Arcus are Critical-Angle Transmission (CAT) grating spectrometers consisting of hundreds of co-aligned diffraction gratings. The gratings require thorough quality control along the entire manufacturing process: from bare silicon wafers to CAT grating petal assembly. Period variation, grating bar tilt angles, misalignment, and grating film buckling are potential errors of interest which could degrade the performance of the x-ray grating spectrometer. We present progress towards development of metrology techniques to measure and manage aforementioned errors during the entire alignment and integration processes: starting right after fabrication of CAT grating membranes to their assembly into large arrays. A scanning laser reflection tool (SLRT) was developed to measure period variations, alignment, and area percentage of pinched grating bars. An array of four CAT gratings was successfully aligned to satisfy Arcus alignment allocations for a grating window alignment test (GWAT). No discernible signal was found from an effort to measure a ‘half’ diffraction order to characterize stiction between grating bars. A metrology protocol was developed to measure grating bar tilt angle variations and average bar tilt angles relative to the grating surface normal, based on small-angle x-ray scattering (SAXS, Cu-Kα) and an optical surface normal measurement (OSNM) setup. A grating holder was designed with integrated slits to relate independent measurements from two different setups using visible and x-ray beams. Bar tilt variations of 1 degree and average bar tilt angles of ~0.3 degree were observed for seven different CAT grating samples. Bar tilt angle variations induced from buckled grating films were also measured. We discuss implications for a more demanding CAT grating spectrometer for the proposed Lynx X-ray Surveyor mission to be presented to the next Astrophysics Decadal Survey.

Proceedings Article | 6 July 2018 Paper

Blazed transmission grating technology development for the Arcus x-ray spectrometer explorer

Ralf Heilmann, Alexander Bruccoleri, Jungki Song, Casey DeRoo, Peter Cheimetz, Edward Hertz, Randall Smith, Vadim Burwitz, Gisela Hartner, Marlis-Madeleine La Caria, Carlo Pelliciari, Hans Guenther, Sarah N. Heine, Beverly LaMarr, Herman Marshall, Norbert Schulz, Eric Gullikson, Mark Schattenburg

Proceedings Volume 10699, 106996D (2018) https://doi.org/10.1117/12.2314180

KEYWORDS: Diffraction gratings, X-rays, Spectroscopy, Optical alignment, Diffraction, Optical design, Silicon, Charge-coupled devices, X-ray technology

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Proceedings Article | 29 August 2017 Paper

Critical-angle transmission grating technology development for high resolving power soft x-ray spectrometers on Arcus and Lynx

Ralf Heilmann, Alexander Bruccoleri, Jungki Song, Jeffery Kolodziejczak, Jessica Gaskin, Stephen O'Dell, Peter Cheimetz, Edward Hertz, Randall Smith, Vadim Burwitz, Gisela Hartner, Marlis-Madeleine La Caria, Mark Schattenburg

Proceedings Volume 10399, 1039914 (2017) https://doi.org/10.1117/12.2273000

KEYWORDS: Diffraction gratings, X-rays, Computed tomography, Spectral resolution, X-ray diffraction, Spectroscopy, Diffraction, Spectrometers, Optical fabrication, Physics

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Soft x-ray spectroscopy with high resolving power (R = λ/Δλ) and large effective area (A) addresses numerous unanswered science questions about the physical laws that lead to the structure of our universe. In the soft x-ray band R > 1000 can currently only be achieved with diffraction grating-based spectroscopy. Criticalangle transmission (CAT) gratings combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (relaxed alignment tolerances and temperature requirements, transparent at higher energies, low mass), resulting in minimal mission resource requirements, while greatly improving figures of merit. Diffraction efficiency > 33% and R > 10, 000 have been demonstrated for CAT gratings. Last year the technology has been certified at Technology Readiness Level 4 based on a probe class mission concept. The Explorer-scale (A > 450 cm² , R > 2500) grating spectroscopy Arcus mission can be built with today's CAT grating technology and has been selected in the current Explorer round for a Phase A concept study. Its figure of merit for the detection of weak absorption lines will be an order of magnitude larger than current instruments on Chandra and XMM-Newton. Further CAT grating technology development and improvements in the angular resolution of x-ray optics can provide another order of magnitude improvement in performance, as is envisioned for the X-ray Surveyor/Lynx mission concept currently under development for input into the 2020 Decadal Survey. For Arcus we have tested CAT gratings in a spectrometer setup in combination with silicon pore optics (SPO) and obtained resolving power results that exceed Arcus requirements before and after environmental testing of the gratings. We have recently fabricated the largest (32 mm x 32 mm) CAT gratings to date, and plan to increase grating size further. We mounted two of these large gratings to frames and aligned them in the roll direction using a laser-based technique. Simultaneous x-ray illumination of both gratings with an SPO module demonstrated that we can exceed Arcus grating-to-grating alignment requirements without x rays.

Proceedings Article | 29 August 2017 Paper

Scanning laser reflection tool for alignment and period measurement of critical-angle transmission gratings

Jungki Song, Ralf Heilmann, Alexander Bruccoleri, Edward Hertz, Mark Schatternburg

Proceedings Volume 10399, 1039915 (2017) https://doi.org/10.1117/12.2274206

KEYWORDS: Computed tomography, X-rays, Reflection, Lawrencium, Spectral resolution, Laser development, X-ray lasers, X-ray technology, Spectroscopy, Observatories

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Showing 5 of 9 publications

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