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Title: OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS

Abstract

We report on recent progress for the development of a new cold X-ray optical test capability using the Omega Facility located at the Laboratory for Laser Energetics (LLE) at the University of Rochester. These tests were done on the 30 kJ OMEGA laser at the Laboratory for Laser Energetics (LLE) at the University of Rochester, Rochester, NY. We conducted a six-shot series called OMEGA II on 14 July 2006 in one eight-hour day (supported by the Defense Threat Reduction Agency). The initial testing was performed using simple protected gold optical coatings on fused silica substrates. PUFFTFT analyses were completed and the specimen's thermal lateral stress and transverse stress conditions were calculated and interpreted. No major anomalies were detected. Comparison of the pre- and posttest reflective measurements coupled with the TFCALC analyses proved invaluable in guiding the analyses and interpreting the observed damage. The Omega facility is a high quality facility for performing evaluation of optical coatings and coupons and provides experience for the development of future National Ignition Facility (NIF) testing.

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
971784
Report Number(s):
UCRL-JRNL-230641
TRN: US201004%%282
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Radiation Effects, Research and Engineering, vol. 26, no. 1, December 31, 2009, pp. 59-70; Journal Volume: 26; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUMM MECHANICS, GENERAL PHYSICS; COATINGS; EVALUATION; GOLD; LASERS; OMEGA FACILITY; SILICA; SIMULATION; SUBSTRATES; TESTING; US NATIONAL IGNITION FACILITY

Citation Formats

Fisher, J H, Newlander, C D, Fournier, K B, Beutler, D E, Coverdale, C A, May, M J, Tobin, M, Davis, J F, and Shiekh, D. OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS. United States: N. p., 2007. Web.
Fisher, J H, Newlander, C D, Fournier, K B, Beutler, D E, Coverdale, C A, May, M J, Tobin, M, Davis, J F, & Shiekh, D. OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS. United States.
Fisher, J H, Newlander, C D, Fournier, K B, Beutler, D E, Coverdale, C A, May, M J, Tobin, M, Davis, J F, and Shiekh, D. Fri . "OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS". United States. doi:. https://www.osti.gov/servlets/purl/971784.
@article{osti_971784,
title = {OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS},
author = {Fisher, J H and Newlander, C D and Fournier, K B and Beutler, D E and Coverdale, C A and May, M J and Tobin, M and Davis, J F and Shiekh, D},
abstractNote = {We report on recent progress for the development of a new cold X-ray optical test capability using the Omega Facility located at the Laboratory for Laser Energetics (LLE) at the University of Rochester. These tests were done on the 30 kJ OMEGA laser at the Laboratory for Laser Energetics (LLE) at the University of Rochester, Rochester, NY. We conducted a six-shot series called OMEGA II on 14 July 2006 in one eight-hour day (supported by the Defense Threat Reduction Agency). The initial testing was performed using simple protected gold optical coatings on fused silica substrates. PUFFTFT analyses were completed and the specimen's thermal lateral stress and transverse stress conditions were calculated and interpreted. No major anomalies were detected. Comparison of the pre- and posttest reflective measurements coupled with the TFCALC analyses proved invaluable in guiding the analyses and interpreting the observed damage. The Omega facility is a high quality facility for performing evaluation of optical coatings and coupons and provides experience for the development of future National Ignition Facility (NIF) testing.},
doi = {},
journal = {Journal of Radiation Effects, Research and Engineering, vol. 26, no. 1, December 31, 2009, pp. 59-70},
number = 1,
volume = 26,
place = {United States},
year = {Fri Apr 27 00:00:00 EDT 2007},
month = {Fri Apr 27 00:00:00 EDT 2007}
}
  • A two-mirror normal-incidence microscope with multilayer coatings was used to image the soft-x-ray emissions from planar foils irradiated by OMEGA laser beams. The bandpass of the multilayer coatings was centered at a wavelength of 48.3 {Angstrom} (257-eV energy) and was 0.5 {Angstrom} wide. Five overlapping OMEGA beams, without beam smoothing, were typically incident on the gold foils. The total energy was 1500 J, and the focused intensity was 6{times}10{sup 13} Wcm{sup {minus}2}. The 5.8{times} magnified images were recorded by a gated framing camera at various times during the 3-ns laser pulse. A pinhole camera imaged the x-ray emission in themore » energy range of {gt}2 keV. On a spatial scale of 10 {mu}m, it was found that the soft-x-ray images at 257 eV were quite uniform and featureless. In contrast, the hard-x-ray images in the energy range of {gt}2 kev were highly nonuniform with numerous features of size 150 {mu}m. {copyright} 1998 Optical Society of America« less
  • An analytical study of the on-axis aperture defect (spherical aberration) convolved with diffraction, for a simple spheric-based Kirkpatrick{endash}Baez (KB) grazing incidence x-ray microscope, indicates the optimum performance is achieved by using a short object plane to mirror distances, steep grazing angles, and high x-ray energies. Other aberrations occur for off-axis field points, but if the spherical aberration can be reduced significantly the image improvement of an extended object should be dramatic. In the quest for ultrahigh x-ray spatial resolution, the Los Alamos one-dimensional (1D) KB (at the time of writing, under fabrication) fully exploits these facts in a 40 mmmore » working distance, steep grazing angle multilayer mirror, 4.316 keV design. A rigorous analysis of Zernike surface deformations, and all other fabrication/assembly errors indicates negligible image degradation of the predicted very high resolution performance; a similar study of existing KBs closely models the 3{endash}5 {mu}m resolutions over the relevant field sizes. In addition, a novel analytical and ray trace optimization technique allows larger working distances at even higher resolutions. Due to instrument length constraints, however, this approach was not incorporated into the 4.316 keV 1DKB; although, in the future such designs could be easily accommodated on The National Ignition Facility. {copyright} {ital 1999 American Institute of Physics.}« less
  • Soft x-ray power diagnostics are essential for evaluating high temperature laser plasma experiments. The Dante soft x-ray spectrometer, a core diagnostic for radiation flux and temperature measurements of Hohlraums, installed on the Omega Laser Facility at the Laboratory for Laser Energetics has recently undergone a series of upgrades. Work performed at Brookhaven National Laboratory for the development of the National Ignition Facility (NIF) Dante spectrometer enables the Omega Dante to offer a total of 18 absolutely calibrated channels in the energy range from 50 eV to 20 keV. This feature provides Dante with the capability to measure higher, NIF relevant,more » radiation temperatures with increased accuracy including a differentiation of higher energy radiation such as the Au M and L bands. Diagnostic monitoring using experimental data from directly driven Au spherical shots is discussed.« less
  • The transmission crystal spectrometer (TCS) is approved for taking data at the OMEGA-EP laser facility since 2009 and will be available for the OMEGA target chamber in 2010. TCS utilizes a Cauchois type cylindrically bent transmission crystal geometry with a source to crystal distance of 600 mm. Spectral images are recorded by image plates in four positions, one IP on the Rowland circle and three others at 200, 400, and 600 mm beyond the Rowland circle. An earlier version of TCS was used at LULI on experiments that determined the x-ray source size from spectral line broadening on one IPmore » positioned behind the Rowland circle. TCS has recorded numerous backlighter spectra at EP for point projection radiography and for source size measurements. Hard x-ray source size can be determined from the source broadening of both K shell emission lines and from K absorption edges in the bremsstrahlung continuum, the latter being a new way to measure the spatial extent of the hard x-ray bremsstrahlung continuum.« less