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Wong CS, Strehlow J, Broughton DP, Luedtke SV, Huang CK, Bogale A, Fitzgarrald R, Nedbailo R, Schmidt JL, Schmidt TR, Twardowski J, Van Pelt A, Alvarez MA, Junghans A, Mix LT, Reinovsky RE, Rusby DR, Wang Z, Wolfe B, Albright BJ, Batha SH, Palaniyappan S. Robust unfolding of MeV x-ray spectra from filter stack spectrometer data. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:023301. [PMID: 38341719 DOI: 10.1063/5.0190679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/17/2024] [Indexed: 02/13/2024]
Abstract
We present an inversion method capable of robustly unfolding MeV x-ray spectra from filter stack spectrometer (FSS) data without requiring an a priori specification of a spectral shape or arbitrary termination of the algorithm. Our inversion method is based upon the perturbative minimization (PM) algorithm, which has previously been shown to be capable of unfolding x-ray transmission data, albeit for a limited regime in which the x-ray mass attenuation coefficient of the filter material increases monotonically with x-ray energy. Our inversion method improves upon the PM algorithm through regular smoothing of the candidate spectrum and by adding stochasticity to the search. With these additions, the inversion method does not require a physics model for an initial guess, fitting, or user-selected termination of the search. Instead, the only assumption made by the inversion method is that the x-ray spectrum should be near a smooth curve. Testing with synthetic data shows that the inversion method can successfully recover the primary large-scale features of MeV x-ray spectra, including the number of x-rays in energy bins of several-MeV widths to within 10%. Fine-scale features, however, are more difficult to recover accurately. Examples of unfolding experimental FSS data obtained at the Texas Petawatt Laser Facility and the OMEGA EP laser facility are also presented.
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Affiliation(s)
- C-S Wong
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Strehlow
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D P Broughton
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S V Luedtke
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - C-K Huang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Bogale
- Center for Energy Research, University of California - San Diego, La Jolla, California 92093, USA
| | - R Fitzgarrald
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - R Nedbailo
- Center for High Energy Density Science, University of Texas, Austin, Texas 78712, USA
| | - J L Schmidt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T R Schmidt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Twardowski
- Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | - A Van Pelt
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
- Center for High Energy Density Science, University of Texas, Austin, Texas 78712, USA
| | | | - A Junghans
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L T Mix
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - R E Reinovsky
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D R Rusby
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Z Wang
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B Wolfe
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B J Albright
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S H Batha
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Palaniyappan
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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2
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Gatu Johnson M. Charged particle diagnostics for inertial confinement fusion and high-energy-density physics experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:021104. [PMID: 36859013 DOI: 10.1063/5.0127438] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
MeV-range ions generated in inertial confinement fusion (ICF) and high-energy-density physics experiments carry a wealth of information, including fusion reaction yield, rate, and spatial emission profile; implosion areal density; electron temperature and mix; and electric and magnetic fields. Here, the principles of how this information is obtained from data and the charged particle diagnostic suite currently available at the major US ICF facilities for making the measurements are reviewed. Time-integrating instruments using image plate, radiochromic film, and/or CR-39 detectors in different configurations for ion counting, spectroscopy, or emission profile measurements are described, along with time-resolving detectors using chemical vapor deposited diamonds coupled to oscilloscopes or scintillators coupled to streak cameras for measuring the timing of ion emission. A brief description of charged-particle radiography setups for probing subject plasma experiments is also given. The goal of the paper is to provide the reader with a broad overview of available capabilities, with reference to resources where more detailed information can be found.
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Affiliation(s)
- M Gatu Johnson
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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3
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Ehrlich Y, Levy I, Fraenkel M. Calibration of image plate and back illuminated charge coupled device detectors at the thermal emission band of high Z target laser produced plasmas (80-800 eV). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:083510. [PMID: 36050101 DOI: 10.1063/5.0098781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
We present a systematic method to absolutely calibrate detector efficiency vs photon energy using a laser produced plasma broadband x-ray source, a gold standard calibrated detector, and transmission gratings (TGs) as dispersive elements. Calibration uses one calibrated TG and a calibrated gold standard detector on one channel and a second calibrated TG and a detector to be calibrated on the other channel. Both channels simultaneously view the laser-produced plasma x-ray source from the same angle with respect to the laser beam and the planar target normal. Image plate detectors are calibrated for the first time at photon energies below 700 eV. Single shot simultaneous calibration of several detectors is possible, making this method an efficient and practical way to periodically calibrate detectors, using in-house capabilities of laser laboratories.
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Affiliation(s)
- Y Ehrlich
- Plasma Physics Department, Soreq NRC, Yavne 81800, Israel
| | - I Levy
- Plasma Physics Department, Soreq NRC, Yavne 81800, Israel
| | - M Fraenkel
- Plasma Physics Department, Soreq NRC, Yavne 81800, Israel
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4
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Hall GN, Krauland CM, Schollmeier MS, Kemp GE, Buscho JG, Hibbard R, Thompson N, Casco ER, Ayers MJ, Ayers SL, Meezan NB, Hopkins LFB, Nora R, Hammel BA, Masse L, Field JE, Bradley DK, Bell P, Landen OL, Kilkenny JD, Mariscal D, Park J, McCarville TJ, Lowe-Webb R, Kalantar D, Kohut T, Piston K. The Crystal Backlighter Imager: A spherically bent crystal imager for radiography on the National Ignition Facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:013702. [PMID: 30709218 DOI: 10.1063/1.5058700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/17/2018] [Indexed: 06/09/2023]
Abstract
The Crystal Backlighter Imager (CBI) is a quasi-monochromatic, near-normal incidence, spherically bent crystal imager developed for the National Ignition Facility (NIF), which will allow inertial confinement fusion capsule implosions to be radiographed close to stagnation. This is not possible using the standard pinhole-based area-backlighter configuration, as the self-emission from the capsule hotspot overwhelms the backlighter signal in the final stages of the implosion. The CBI mitigates the broadband self-emission from the capsule hot spot by using the extremely narrow bandwidth inherent to near-normal-incidence Bragg diffraction. Implementing a backlighter system based on near-normal reflection in the NIF chamber presents unique challenges, requiring the CBI to adopt novel engineering and operational strategies. The CBI currently operates with an 11.6 keV backlighter, making it the highest energy radiography diagnostic based on spherically bent crystals to date. For a given velocity, Doppler shift is proportional to the emitted photon energy. At 11.6 keV, the ablation velocity of the backlighter plasma results in a Doppler shift that is significant compared to the bandwidth of the instrument and the width of the atomic line, requiring that the shift be measured to high accuracy and the optics aligned accordingly to compensate. Experiments will be presented that used the CBI itself to measure the backlighter Doppler shift to an accuracy of better than 1 eV. These experiments also measured the spatial resolution of CBI radiographs at 7.0 μm, close to theoretical predictions. Finally, results will be presented from an experiment in which the CBI radiographed a capsule implosion driven by a 1 MJ NIF laser pulse, demonstrating a significant (>100) improvement in the backlighter to self-emission ratio compared to the pinhole-based area-backlighter configuration.
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Affiliation(s)
- G N Hall
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - C M Krauland
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M S Schollmeier
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G E Kemp
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - J G Buscho
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - R Hibbard
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - N Thompson
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - E R Casco
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - M J Ayers
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - S L Ayers
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - N B Meezan
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - L F Berzak Hopkins
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - R Nora
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - B A Hammel
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - L Masse
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - J E Field
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - D K Bradley
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - P Bell
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - O L Landen
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - J D Kilkenny
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - D Mariscal
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - J Park
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - T J McCarville
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - R Lowe-Webb
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - D Kalantar
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - T Kohut
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - K Piston
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
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Rosenberg MJ, Thorn DB, Izumi N, Williams D, Rowland M, Torres G, Haugh M, Hillyard P, Adelman N, Schuler T, Barrios MA, Holder JP, Schneider MB, Fournier KB, Bradley DK, Regan SP. Image-plate sensitivity to x rays at 2 to 60 keV. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:013506. [PMID: 30709229 DOI: 10.1063/1.5053592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 01/08/2019] [Indexed: 06/09/2023]
Abstract
The sensitivity of Fuji SR and MS image plates (IPs) used in x-ray spectrometers on OMEGA and the National Ignition Facility has been measured using two techniques. A set of radioisotopes has been used to constrain image-plate sensitivity between 6 and 60 keV, while a Manson source has been used to expose image plates to x rays at energies between 1.5 and 8 keV. These data have shown variation in sensitivity on the order of 5% for a given IP type and scanner settings. The radioisotope technique has also been used to assess IP fading properties for MS-type plates over long times. IP sensitivity as a function of scanner settings and pixel size has been systematically examined, showing variations of up to a factor of 2 depending on the IP type. Cross-calibration of IP scanners at different facilities is necessary to produce a consistent absolute sensitivity curve spanning the energy range of 2-60 keV.
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Affiliation(s)
- M J Rosenberg
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - D B Thorn
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Izumi
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D Williams
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M Rowland
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - G Torres
- Mission Support and Test Services, LLC, Livermore, California 94551, USA
| | - M Haugh
- Mission Support and Test Services, LLC, Livermore, California 94551, USA
| | - P Hillyard
- Mission Support and Test Services, LLC, Livermore, California 94551, USA
| | - N Adelman
- California Polytechnic State University, San Luis Obispo, California 93407, USA
| | - T Schuler
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M A Barrios
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J P Holder
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - K B Fournier
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D K Bradley
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
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6
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Thorn DB, Coppari F, Döppner T, MacDonald MJ, Regan SP, Schneider MB. X-ray spectrometer throughput model for (selected) flat Bragg crystal spectrometers on laser plasma facilities. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10F119. [PMID: 30399669 DOI: 10.1063/1.5039423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/24/2018] [Indexed: 06/08/2023]
Abstract
At large laser faculties, such as OMEGA and the National Ignition Facility (NIF), x-ray spectrometers are provided by the facility to diagnose plasma conditions or monitor backlighters. Often the calibration of these spectrometers is unknown or out of date. As a remedy to this situation, we present a simple ray trace method to calibrate flat crystal spectrometers using only basic information regarding the optical design of the spectrometer. This model is then used to output photometric throughput estimates, dispersion, solid angle, and spectral resolution estimates. This model is applied to the mono angle crystal spectrometer and Super Snout I at the NIF and the X-Ray Spectrometer at the OMEGA laser facility.
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Affiliation(s)
- D B Thorn
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - F Coppari
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T Döppner
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M J MacDonald
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S P Regan
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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