1
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Nagayama T, Bailey JE, Loisel GP, Dunham GS, Rochau GA, Blancard C, Colgan J, Cossé P, Faussurier G, Fontes CJ, Gilleron F, Hansen SB, Iglesias CA, Golovkin IE, Kilcrease DP, MacFarlane JJ, Mancini RC, More RM, Orban C, Pain JC, Sherrill ME, Wilson BG. Systematic Study of L-Shell Opacity at Stellar Interior Temperatures. PHYSICAL REVIEW LETTERS 2019; 122:235001. [PMID: 31298873 DOI: 10.1103/physrevlett.122.235001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Indexed: 06/10/2023]
Abstract
The first systematic study of opacity dependence on atomic number at stellar interior temperatures is used to evaluate discrepancies between measured and modeled iron opacity [J. E. Bailey et al., Nature (London) 517, 56 (2015)NATUAS0028-083610.1038/nature14048]. High-temperature (>180 eV) chromium and nickel opacities are measured with ±6%-10% uncertainty, using the same methods employed in the previous iron experiments. The 10%-20% experiment reproducibility demonstrates experiment reliability. The overall model-data disagreements are smaller than for iron. However, the systematic study reveals shortcomings in models for density effects, excited states, and open L-shell configurations. The 30%-45% underestimate in the modeled quasicontinuum opacity at short wavelengths was observed only from iron and only at temperature above 180 eV. Thus, either opacity theories are missing physics that has nonmonotonic dependence on the number of bound electrons or there is an experimental flaw unique to the iron measurement at temperatures above 180 eV.
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Affiliation(s)
- T Nagayama
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - J E Bailey
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G P Loisel
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G S Dunham
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G A Rochau
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | | | - J Colgan
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Ph Cossé
- CEA, DAM, DIF, F-91297 Arpajon, France
| | | | - C J Fontes
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | | | - S B Hansen
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - C A Iglesias
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - I E Golovkin
- Prism Computational Sciences, Madison, Wisconsin 53711, USA
| | - D P Kilcrease
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J J MacFarlane
- Prism Computational Sciences, Madison, Wisconsin 53711, USA
| | - R C Mancini
- University of Nevada, Reno, Nevada 89557, USA
| | - R M More
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - C Orban
- Ohio State University, Columbus, Ohio 43210, USA
| | - J-C Pain
- CEA, DAM, DIF, F-91297 Arpajon, France
| | - M E Sherrill
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B G Wilson
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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2
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King JA, Opachich YP, Huffman EJ, Knight R, Heeter RF, Ahmed M, Liedahl DA, Schneider MB, Thompson NB, Johns HM, Dodd E, Flippo KA, Kline JL, Lopez FE, Archuleta TN, Perry TS. Implementation of a 1-2 keV point-projection x-ray spectrometer on the National Ignition Facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10F101. [PMID: 30399753 DOI: 10.1063/1.5038092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/12/2018] [Indexed: 06/08/2023]
Abstract
A point-projection soft X-ray Opacity Spectrometer (OpSpec) has been implemented to measure X-ray spectra from ∼1 to 2 keV on the National Ignition Facility (NIF). Measurement of such soft X-rays with open-aperture point-projection detectors is challenging because only very thin filters may be used to shield the detector from the hostile environment. OpSpec diffracts X-rays from 540 to 2100 eV off a potassium (or rubidium) acid phthalate (KAP or RbAP) crystal onto either image plates or, most recently, X-ray films. A "sacrificial front filter" strategy is used to prevent crystal damage, while 2 or 3 rear filters protect the data. Since May 2017, OpSpec has been recording X-ray transmission data for iron-magnesium plasmas on the NIF, at "Anchor 1" plasma conditions (temperature ∼150 eV, density ∼7 × 1021 e -/cm3). Upgrades improved OpSpec's performance on 6 NIF shots in August and December 2017, with reduced backgrounds and 100% data return using filter stacks as thin as 2.9 μm (total). Photometric noise is beginning to meet requirements, and further work will reduce systematic errors.
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Affiliation(s)
- J A King
- Nevada National Security Site, Livermore, California 94550, USA
| | - Y P Opachich
- Nevada National Security Site, Livermore, California 94550, USA
| | - E J Huffman
- Nevada National Security Site, Livermore, California 94550, USA
| | - R Knight
- Nevada National Security Site, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Ahmed
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N B Thompson
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - H M Johns
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E Dodd
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K A Flippo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J L Kline
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F E Lopez
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T N Archuleta
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T S Perry
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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3
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Stillman CR, Nilson PM, Sefkow AB, Ivancic ST, Mileham C, Begishev IA, Froula DH. Energy transfer dynamics in strongly inhomogeneous hot-dense-matter systems. Phys Rev E 2018; 97:063208. [PMID: 30011604 DOI: 10.1103/physreve.97.063208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Indexed: 11/07/2022]
Abstract
Direct measurements of energy transfer across steep density and temperature gradients in a hot-dense-matter system are presented. Hot-dense-plasma conditions were generated by high-intensity laser irradiation of a thin-foil target containing a buried metal layer. Energy transfer to the layer was measured using picosecond time-resolved x-ray emission spectroscopy. The data show two x-ray flashes in time. Fully explicit, coupled particle-in-cell and collisional-radiative atomic kinetics model predictions reproduce these observations, connecting the two x-ray flashes with staged radial energy transfer within the target.
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Affiliation(s)
- C R Stillman
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.,Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - P M Nilson
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - A B Sefkow
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.,Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.,Department of Mechanical Engineering, University of Rochester, Rochester, New York 14623, USA
| | - S T Ivancic
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - C Mileham
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - I A Begishev
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA.,Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
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4
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Lee RW. The Possibilities for Scientific Use of High-Energy Lasers: From Now to the NIF. ACTA ACUST UNITED AC 2018. [DOI: 10.13182/fst96-a11962992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Richard W. Lee
- Physics Department, University of California Berkeley 366 Le Conte Hall Berkeley CA 94720-7300 and Lawrence Livermore National Laboratory Livermore CA 94550
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5
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Cho BI, Cho MS, Kim M, Chung HK, Barbrel B, Engelhorn K, Burian T, Chalupský J, Ciricosta O, Dakovski GL, Hájková V, Holmes M, Juha L, Krzywinski J, Lee RW, Nam CH, Rackstraw DS, Toleikis S, Turner JJ, Vinko SM, Wark JS, Zastrau U, Heimann PA. Observation of Reverse Saturable Absorption of an X-ray Laser. PHYSICAL REVIEW LETTERS 2017; 119:075002. [PMID: 28949680 DOI: 10.1103/physrevlett.119.075002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Indexed: 06/07/2023]
Abstract
A nonlinear absorber in which the excited state absorption is larger than the ground state can undergo a process called reverse saturable absorption. It is a well-known phenomenon in laser physics in the optical regime, but is more difficult to generate in the x-ray regime, where fast nonradiative core electron transitions typically dominate the population kinetics during light matter interactions. Here, we report the first observation of decreasing x-ray transmission in a solid target pumped by intense x-ray free electron laser pulses. The measurement has been made below the K-absorption edge of aluminum, and the x-ray intensity ranges are 10^{16} -10^{17} W/cm^{2}. It has been confirmed by collisional radiative population kinetic calculations, underscoring the fast spectral modulation of the x-ray pulses and charge states relevant to the absorption and transmission of x-ray photons. The processes shown through detailed simulations are consistent with reverse saturable absorption, which would be the first observation of this phenomena in the x-ray regime. These light matter interactions provide a unique opportunity to investigate optical transport properties in the extreme state of matters, as well as affording the potential to regulate ultrafast x-ray free-electron laser pulses.
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Affiliation(s)
- B I Cho
- Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - M S Cho
- Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - M Kim
- Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - H-K Chung
- Atomic and Molecular Data Unit, Nuclear Data Section, IAEA, P.O. Box 100, A-1400 Vienna, Austria
| | - B Barbrel
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - K Engelhorn
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - T Burian
- Institute of Physics ASCR, Na Slovance 2, 18221 Prague 8, Czech Republic
| | - J Chalupský
- Institute of Physics ASCR, Na Slovance 2, 18221 Prague 8, Czech Republic
| | - O Ciricosta
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - G L Dakovski
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - V Hájková
- Institute of Physics ASCR, Na Slovance 2, 18221 Prague 8, Czech Republic
| | - M Holmes
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - L Juha
- Institute of Physics ASCR, Na Slovance 2, 18221 Prague 8, Czech Republic
| | - J Krzywinski
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - R W Lee
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Chang Hee Nam
- Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005, Korea
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - D S Rackstraw
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - S Toleikis
- Deutsches-Elektronensynchrotron DESY, Notkestrasse 85, D-22603 Hamburg, Germany
| | - J J Turner
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - S M Vinko
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - J S Wark
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - U Zastrau
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - P A Heimann
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
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6
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Opachich YP, Heeter RF, Barrios MA, Garcia EM, Craxton RS, King JA, Liedahl DA, McKenty PW, Schneider MB, May MJ, Zhang R, Ross PW, Kline JL, Moore AS, Weaver JL, Flippo KA, Perry TS. Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility. PHYSICS OF PLASMAS 2017; 24:063301. [PMID: 29104422 PMCID: PMC5648568 DOI: 10.1063/1.4985076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ∼20 μm thickness have been performed. X-ray yields of up to ∼1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ∼100 μm FWHM, with ∼350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.
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Affiliation(s)
- Y P Opachich
- National Security Technologies, LLC, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M A Barrios
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E M Garcia
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - R S Craxton
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J A King
- National Security Technologies, LLC, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P W McKenty
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M J May
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Zhang
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - P W Ross
- National Security Technologies, LLC, Livermore, California 94550, USA
| | - J L Kline
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J L Weaver
- Naval Research Laboratory, Washington, D.C. 20375, USA
| | - K A Flippo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T S Perry
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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7
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Stillman CR, Nilson PM, Ivancic ST, Golovkin IE, Mileham C, Begishev IA, Froula DH. Picosecond time-resolved measurements of dense plasma line shifts. Phys Rev E 2017; 95:063204. [PMID: 28709197 DOI: 10.1103/physreve.95.063204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Indexed: 06/07/2023]
Abstract
Picosecond time-resolved x-ray spectroscopy is used to measure the spectral line shift of the 1s2p-1s^{2} transition in He-like Al ions as a function of the instantaneous plasma conditions. The plasma temperature and density are inferred from the Al He_{α} complex using a nonlocal-thermodynamic-equilibrium atomic physics model. The experimental spectra show a linearly increasing redshift for electron densities of 1-5×10^{23}cm^{-3}. The measured line shifts are broadly consistent with a generalized analytic line-shift model based on calculations of a self-consistent field ion-sphere model.
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Affiliation(s)
- C R Stillman
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - P M Nilson
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - S T Ivancic
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - I E Golovkin
- Prism Computational Sciences, Madison, Wisconsin 53711, USA
| | - C Mileham
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - I A Begishev
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
| | - D H Froula
- Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
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8
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Ross PW, Heeter RF, Ahmed MF, Dodd E, Huffman EJ, Liedahl DA, King JA, Opachich YP, Schneider MB, Perry TS. Design of the opacity spectrometer for opacity measurements at the National Ignition Facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11D623. [PMID: 27910379 DOI: 10.1063/1.4962819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent experiments at the Sandia National Laboratory Z facility have called into question models used in calculating opacity, of importance for modeling stellar interiors. An effort is being made to reproduce these results at the National Ignition Facility (NIF). These experiments require a new X-ray opacity spectrometer (OpSpec) spanning 540 eV-2100 eV with a resolving power E/ΔE > 700. The design of the OpSpec is presented. Photometric calculations based on expected opacity data are also presented. First use on NIF is expected in September 2016.
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Affiliation(s)
- P W Ross
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - M F Ahmed
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - E Dodd
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, USA
| | - E J Huffman
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - J A King
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - Y P Opachich
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - T S Perry
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, USA
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9
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Keiter PA, Drake RP. Spectral measurements of asymmetrically irradiated capsule backlighters. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11E338. [PMID: 27910530 DOI: 10.1063/1.4961555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies [J. F. Hansen et al., Rev. Sci. Instrum. 79, 013504 (2008)]. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of 2-13 keV and time-resolved spectra over the photon energy range of 2-3 keV. We will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.
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Affiliation(s)
- P A Keiter
- Department of Climate and Space Sciences Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
| | - R P Drake
- Department of Climate and Space Sciences Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA
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10
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Nagayama T, Bailey JE, Loisel G, Rochau GA, MacFarlane JJ, Golovkin I. Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions. Phys Rev E 2016; 93:023202. [PMID: 26986427 DOI: 10.1103/physreve.93.023202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Indexed: 06/05/2023]
Abstract
Recently, frequency-resolved iron opacity measurements at electron temperatures of 170-200 eV and electron densities of (0.7-4.0)×10(22)cm(-3) revealed a 30-400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. These simulations bridge the static-uniform picture of the data interpretation and the dynamic-gradient reality of the experiments, and they will allow us to quantitatively assess the impact of effects neglected in the data interpretation.
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Affiliation(s)
- T Nagayama
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - J E Bailey
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G Loisel
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - G A Rochau
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - J J MacFarlane
- Prism Computational Sciences, Madison, Wisconsin 53703, USA
| | - I Golovkin
- Prism Computational Sciences, Madison, Wisconsin 53703, USA
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11
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Knapp PF, Hansen SB, Pikuz SA, Shelkovenko TA, Hammer DA. Calibration and analysis of spatially resolved x-ray absorption spectra from a nonuniform plasma. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:073502. [PMID: 22852690 DOI: 10.1063/1.4731664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 06/13/2012] [Indexed: 06/01/2023]
Abstract
We report here the calibration and analysis techniques used to obtain spatially resolved density and temperature measurements of a pair of imploding aluminum wires from x-ray absorption spectra. A step wedge is used to measure backlighter fluence at the film, allowing transmission through the sample to be measured with an accuracy of ±14% or better. A genetic algorithm is used to search the allowed plasma parameter space and fit synthetic spectra with 20 μm spatial resolution to the measured spectra, taking into account that the object plasma nonuniformity must be physically reasonable. The inferred plasma conditions must be allowed to vary along the absorption path in order to obtain a fit to the spectral data. The temperature is estimated to be accurate to within ±25% and the density to within a factor of two. This information is used to construct two-dimensional maps of the density and temperature of the object plasma.
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Affiliation(s)
- P F Knapp
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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12
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Blenski T, Loisel G, Poirier M, Thais F, Arnault P, Caillaud T, Fariaut J, Gilleron F, Pain JC, Porcherot Q, Reverdin C, Silvert V, Villette B, Bastiani-Ceccotti S, Turck-Chièze S, Foelsner W, de Gaufridy de Dortan F. Opacity of iron, nickel, and copper plasmas in the x-ray wavelength range: theoretical interpretation of 2p-3d absorption spectra. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:036407. [PMID: 22060513 DOI: 10.1103/physreve.84.036407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 06/30/2011] [Indexed: 05/31/2023]
Abstract
This paper deals with theoretical studies on the 2p-3d absorption in iron, nickel, and copper plasmas related to LULI2000 (Laboratoire pour l'Utilisation des Lasers Intenses, 2000J facility) measurements in which target temperatures were of the order of 20 eV and plasma densities were in the range 0.004-0.01 g/cm(3). The radiatively heated targets were close to local thermodynamic equilibrium (LTE). The structure of 2p-3d transitions has been studied with the help of the statistical superconfiguration opacity code SCO and with the fine-structure atomic physics codes HULLAC and FAC. A new mixed version of the sco code allowing one to treat part of the configurations by detailed calculation based on the Cowan's code RCG has been also used in these comparisons. Special attention was paid to comparisons between theory and experiment concerning the term features which cannot be reproduced by SCO. The differences in the spin-orbit splitting and the statistical (thermal) broadening of the 2p-3d transitions have been investigated as a function of the atomic number Z. It appears that at the conditions of the experiment the role of the term and configuration broadening was different in the three analyzed elements, this broadening being sensitive to the atomic number. Some effects of the temperature gradients and possible non-LTE effects have been studied with the help of the radiative-collisional code SCRIC. The sensitivity of the 2p-3d structures with respect to temperature and density in medium-Z plasmas may be helpful for diagnostics of LTE plasmas especially in future experiments on the Δn=0 absorption in medium-Z plasmas for astrophysical applications.
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Affiliation(s)
- T Blenski
- CEA, IRAMIS, Service Photons, Atomes et Molécules, Centre d'Études de Saclay, F-91191 Gif-sur-Yvette Cedex, France.
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13
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Knapp PF, Pikuz SA, Shelkovenko TA, Hammer DA, Hansen SB. High resolution absorption spectroscopy of exploding wire plasmas using an x-pinch x-ray source and spherically bent crystal. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:063501. [PMID: 21721685 DOI: 10.1063/1.3592582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 04/29/2011] [Indexed: 05/31/2023]
Abstract
We present here the use of absorption spectroscopy of the continuum radiation from x-pinch-produced point x-ray sources as a diagnostic to investigate the properties of aluminum plasmas created by pulsed power machines. This technique is being developed to determine the charge state, temperature, and density as a function of time and space under conditions that are inaccessible to x-ray emission spectroscopic diagnostics. The apparatus and its characterization are described, and the spectrometer dispersion, magnification, and resolution are calculated and compared with experimental results. Spectral resolution of about 5000 and spatial resolution of about 20 μm are demonstrated. This spectral resolution is the highest available to date in an absorption experiment. The beneficial properties of the x-pinch x-ray source as the backlighter for this diagnostic are the small source size (<5 μm), smooth continuum radiation, and short pulse duration (<0.1 ns). Results from a closely spaced (1 mm) exploding wire pair are shown and the general features are discussed.
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Affiliation(s)
- P F Knapp
- Laboratory of Plasma Studies, Cornell University, 439 Rhodes Hall, Ithaca, New York 14853, USA
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14
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Xiong G, Hu Z, Li H, Zhao Y, Shang W, Zhu T, Wei M, Yang G, Zhang J, Yang J. One-dimensional space resolving flat-field holographic grating soft x-ray framing camera spectrograph for laser plasma diagnostics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:043109. [PMID: 21528997 DOI: 10.1063/1.3579494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A 1D space resolving x-ray spectrum diagnostic system has been developed to study the radiation opacity of hot plasma on SG-II laser facility. The diagnostic system consists of a 2400 lines/mm flat-field holographic grating and a gated microchannel plate coupled with an optical CCD and covers the wavelength range of 5-50 Å. The holographic grating was compared with a ruled one by measuring the emission spectra from a laser-produced molybdenum plasma. The results indicate that the holographic grating possesses better sensitivity than the ruled grating having nearly similar spectral resolution. The spectrograph has been used in radiative opacity measurement of Fe plasma. Simultaneous measurements of the backlight source and the transmission spectrum in appointed time range in one shot have been accomplished successfully with the holographic grating spectrometer. The 2p-3d transition absorption of Fe plasma near 15.5 Å in has been observed clearly.
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Affiliation(s)
- Gang Xiong
- Research Center of Laser Fusion, China Academy of Engineering Physics, P.O. Box 919-986, Mianyang 621900, People's Republic of China
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15
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Zhao Y, Yang J, Zhang J, Liu J, Yuan X, Jin F. Diagnostic development in precise opacity measurement of radiatively heated Al plasma on Shenguang II laser facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:043505. [PMID: 19405658 DOI: 10.1063/1.3116483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Simultaneous measurements of the self-emission spectrum, the backlighting source spectrum, and the transmission spectrum in one shot, which reduce the experimental uncertainties from shot-to-shot fluctuation, are essential for precise opacity experiments. In order to achieve precise absorption spectrum of Al plasmas, a special half sample sandwich target was designed and short backlighter was used to provide time- and space-resolving diagnostics on the Shenguang II high power laser facility. In the measurement, a cylindrical cavity with CH foam baffles was used to provide a clean x-ray radiation environment for sample heating. The x-ray source spectrum, the transmission spectrum, and the self-emission spectrum of the soft x-ray heated Al sample were recorded in one shot with a penta-erythritol tetrakis (hydroxymethy) methane C(CH(2)OH)(4) (PET) crystal spectrometer by using the point-projection method. Experimental results have been compared with the calculation results of a detailed level accounting opacity code.
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Affiliation(s)
- Yang Zhao
- Wuhan National Laboratory for Optoelectronics, Institute of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
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16
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Zhang J, Yang J, Xu Y, Yang G, Ding Y, Yan J, Yuan J, Ding Y, Zheng Z, Zhao Y, Hu Z. Radiative heating of plastic-tamped aluminum foil by x rays from a foam-buffered hohlraum. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2009; 79:016401. [PMID: 19257142 DOI: 10.1103/physreve.79.016401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Revised: 10/20/2008] [Indexed: 05/27/2023]
Abstract
The time dependence of the x-ray absorption of aluminum samples heated with intense radiation sources from a foam-buffered gold hohlraum has been studied in this work. Hydrodynamic simulations were used to illustrate the plasma conditions in the plastic-tamped aluminum foils contained in this type of hohlraum. Experiments were conducted to measure the K -shell x-ray absorption spectra of the aluminum sample. With densities taken from the hydrodynamic simulations, electron temperatures were then inferred by fitting the measured absorption spectra with detailed-term-accounting calculations. The inferred temperatures have a maximum of about 93eV and were found to agree within 25% with the simulated results at times after 1ns , indicating that the use of foam shields, together with a compact cavity, has created a clean and high-temperature radiation source preferable to opacity measurements.
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Affiliation(s)
- Jiyan Zhang
- Research Center of Laser Fusion, P. O. Box 919-986, Mianyang 621900, China
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17
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Bailey JE, Rochau GA, Mancini RC, Iglesias CA, MacFarlane JJ, Golovkin IE, Pain JC, Gilleron F, Blancard C, Cosse P, Faussurier G, Chandler GA, Nash TJ, Nielsen DS, Lake PW. Diagnosis of x-ray heated Mg/Fe opacity research plasmas. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:113104. [PMID: 19045886 DOI: 10.1063/1.3020710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Understanding stellar interiors, inertial confinement fusion, and Z pinches depends on opacity models for mid-Z plasmas in the 100-300 eV temperature range. These models are complex and experimental validation is crucial. In this paper we describe the diagnosis of the first experiments to measure iron plasma opacity at a temperature high enough to produce the charge states and electron configurations that exist in the solar interior. The dynamic Hohlraum x-ray source at Sandia National Laboratories' Z facility was used to both heat and backlight Mg/Fe CH tamped foils. The backlighter equivalent brightness temperature was estimated to be T(r) approximately 314 eV+/-8% using time-resolved x-ray power and imaging diagnostics. This high brightness is significant because it overwhelms the sample self-emission. The sample transmission in the 7-15.5 A range was measured using two convex potassium acid phthalate crystal spectrometers that view the backlighter through the sample. The average spectral resolution over this range was estimated to be lambda/deltalambda approximately 700 by comparing theoretical crystal resolution calculations with measurements at 7.126, 8.340, and 12.254 A. The electron density was determined to be n(e)=6.9+/-1.7 x 10(21) cm(-3) using the Stark-broadened Mg Hebeta, Hegamma, and Hedelta lines. The temperature inferred from the H-like to He-like Mg line ratios was T(e)=156+/-6 eV. Comparisons with three different spectral synthesis models all have normalized chi(2) that is close to unity, indicating quantitative consistency in the inferred plasma conditions. This supports the reliability of the results and implies the experiments are suitable for testing iron opacity models.
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Affiliation(s)
- J E Bailey
- Sandia National Laboratories, Albuquerque, New Mexico 87185-1196, USA
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18
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19
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Hansen JF, Glendinning SG, Heeter RF, Brockington SJE. Dynamic Hohlraums as x-ray sources in high-energy density science. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:013504. [PMID: 18248031 DOI: 10.1063/1.2804765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The first demonstration of laser driven dynamic Hohlraums (LDDH) as a spectrally smooth backlighter source for opacity and temperature measurements through absorption spectrometry of materials in local thermodynamic equilibrium at temperatures >150 eV has been made. This is a crucial temperature regime for future astrophysics and ignition fusion experiments at the nearly completed National Ignition Facility (NIF) [E. I. Moses and C. R. Wuest, Fusion Sci. Technol. 47, 314 (2005)] at the Lawrence Livermore National Laboratory. The new backlighter consists of a LDDH filled with either krypton or argon that implodes to create an x-ray flash. The properties of this x-ray flash have been measured in experiments at the Omega laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] at the Laboratory for Laser Energetics in Rochester, New York, satisfying all requirements imposed by future experiments: (1) the emission spectrum extends to at least 5.5 keV, well above the maximum x-ray energy ( approximately 3.5 keV) obtained from the previously "best" opacity backlighters (uranium M-shell emission backlighters); (2) the spectrum is smooth and featureless (intensity variation <6% rms), allowing absorption spectrometry through experimental samples; (3) the emission source size is sufficiently small (<50 microm) for projection backlighting through future samples; (4) the emission is bright enough (and twice as bright as imploding hydrogen-filled capsules) for gated spectrometer measurements; (5) the emission duration is optimized ( approximately 100 ps) for the current and future generations of spectrometers; and (6) by using only a small number of beams with limited energy and symmetry for the backlighter (10 out of 60 beams in the Omega experiments), the majority of laser beams are left available for heating sample materials to >150 eV.
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Affiliation(s)
- J F Hansen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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20
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Bailey JE, Rochau GA, Iglesias CA, Abdallah J, Macfarlane JJ, Golovkin I, Wang P, Mancini RC, Lake PW, Moore TC, Bump M, Garcia O, Mazevet S. Iron-plasma transmission measurements at temperatures above 150 eV. PHYSICAL REVIEW LETTERS 2007; 99:265002. [PMID: 18233582 DOI: 10.1103/physrevlett.99.265002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Indexed: 05/25/2023]
Abstract
Measurements of iron-plasma transmission at 156+/-6 eV electron temperature and 6.9+/-1.7 x 10(21) cm(-3) electron density are reported over the 800-1800 eV photon energy range. The temperature is more than twice that in prior experiments, permitting the first direct experimental tests of absorption features critical for understanding solar interior radiation transport. Detailed line-by-line opacity models are in excellent agreement with the data.
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Affiliation(s)
- J E Bailey
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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21
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Zeng J, Yuan J. Spectrally resolved opacities and Rosseland and Planck mean opacities of lowly ionized gold plasmas: a detailed level-accounting investigation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:026401. [PMID: 17930156 DOI: 10.1103/physreve.76.026401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 06/11/2007] [Indexed: 05/25/2023]
Abstract
Calculation details of radiative opacity for lowly ionized gold plasmas by using our developed fully relativistic detailed level-accounting approach are presented to show the importance of accurate atomic data for a quantitative reproduction of the experimental observations. Even though a huge number of transition lines are involved in the radiative absorption of high- Z plasmas so that one believes that statistical models can often give a reasonable description of their opacities, we first show in detail that an adequate treatment of physical effects, in particular the configuration interaction (including the core-valence electron correlation), is essential to produce atomic data of bound-bound and bound-free processes for gold plasmas, which are accurate enough to correctly explain the relative intensity of two strong absorption peaks experimentally observed located near photon energy of 70 and 80 eV. A detailed study is also carried out for gold plasmas of an average ionization degree sequence of 10, for both spectrally resolved opacities and Rosseland and Planck means. For comparison, results obtained by using an average atom model are also given to show that even for a relatively higher density of matter, correlation effects are also important to predict the correct positions of absorption peaks of transition arrays.
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Affiliation(s)
- Jiaolong Zeng
- Department of Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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22
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Zeng J, Yuan J. Radiative opacity of gold plasmas studied by a detailed level-accounting method. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 74:025401. [PMID: 17025496 DOI: 10.1103/physreve.74.025401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Indexed: 05/12/2023]
Abstract
There are systematic discrepancies unexplained so far between theory and experiment for opacities of mid- and high- Z plasmas. To address this issue, we investigated the radiative opacity of gold plasmas by using a detailed level-accounting (DLA) method, in which various physical effects can be taken into account. In this work, we studied in detail the effects of core-valence electron correlation and linewidth on the opacity of gold plasmas. Our DLA results correctly explain the relative intensity of the two strong absorption peaks located near the photon energies of 70 and 80eV , which was experimentally observed by Eidmann [Europhys. Lett. 44, 459 (1998)]. Meanwhile, the DLA results showed that effects of saturation for the strong individual lines are evident in the transmission spectrum.
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Affiliation(s)
- Jiaolong Zeng
- Department of Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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23
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Rochau GA, Bailey JE, Macfarlane JJ. Measurement and analysis of x-ray absorption in Al and MgF2 plasmas heated by Z-pinch radiation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:066405. [PMID: 16486068 DOI: 10.1103/physreve.72.066405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 10/10/2005] [Indexed: 05/06/2023]
Abstract
High-power Z pinches on Sandia National Laboratories' Z facility can be used in a variety of experiments to radiatively heat samples placed some distance away from the Z-pinch plasma. In such experiments, the heating radiation spectrum is influenced by both the Z-pinch emission and the re-emission of radiation from the high-Z surfaces that make up the Z-pinch diode. To test the understanding of the amplitude and spectral distribution of the heating radiation, thin foils containing both Al and MgF2 were heated by a 100-130 TW Z pinch. The heating of these samples was studied through the ionization distribution in each material as measured by x-ray absorption spectra. The resulting plasma conditions are inferred from a least-squares comparison between the measured spectra and calculations of the Al and Mg 1s-->2p absorption over a large range of temperatures and densities. These plasma conditions are then compared to radiation-hydrodynamics simulations of the sample dynamics and are found to agree within 1sigma to the best-fit conditions. This agreement indicates that both the driving radiation spectrum and the heating of the Al and MgF2 samples is understood within the accuracy of the spectroscopic method.
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Affiliation(s)
- Gregory A Rochau
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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24
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Jin F, Yuan J. Detailed diagnostics for a hot bromine plasma by the open M-shell opacity. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:016404. [PMID: 16090096 DOI: 10.1103/physreve.72.016404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Revised: 05/09/2005] [Indexed: 05/03/2023]
Abstract
The experimental transmission spectrum of a hot bromine plasma [J. E. Bailey, J. Quant. Spectrosc. Radiat. Transf. 81, 31 (2003)] has been simulated by using a detailed level accounting model (DLA). With assumption of the local thermodynamic equilibrium, the major absorption lines of the experimental spectrum are well reproduced by the present DLA calculation, and the details of the absorption line shapes are used to determine the temperature of the plasma. In contrast to the results of two former statistical models, where the temperature was determined via a global fitting to the experimental data, the present DLA diagnoses the plasma temperature by the line ratios of different charge states in the 2p-->3d transition groups resulting in a temperature of 37 eV . It is shown that a change of 1 eV in temperature could cause perceptible changes in the simulated spectrum. It is also shown that the 2 p1/2 -->3 d3/2 absorptions have been overestimated by the statistical models.
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Affiliation(s)
- Fengtao Jin
- Department of Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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25
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Stevenson RM, Oades K, Thomas BR, Schneider M, Slark GE, Suter LJ, Kauffman R, Hinkel D, Miller MC. Evidence for high-efficiency laser-heated hohlraum performance at 527 nm. PHYSICAL REVIEW LETTERS 2005; 94:055006. [PMID: 15783658 DOI: 10.1103/physrevlett.94.055006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2004] [Indexed: 05/24/2023]
Abstract
A series of experiments conducted on the HELEN laser system [M. J. Norman, Appl. Opt.4120023497], into thermal x-ray generation from hohlraum targets using 527 nm (2omega) wavelength laser light, has shown that it is possible to exceed radiation temperatures previously thought limited by high levels of superthermal or hot electron production or stimulated backscatter. This Letter questions whether the assumptions traditionally applied to hohlraum design with respect to hot plasma filling and the use of 2omega light are too conservative.
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Affiliation(s)
- R M Stevenson
- Atomic Weapons Establishment, Aldermaston, Reading, Berkshire RG7 4PR, United Kingdom
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26
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Jin F, Zeng J, Yuan J. Radiative opacities and configuration interaction effects of hot iron plasma using a detailed term accounting model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 68:066401. [PMID: 14754321 DOI: 10.1103/physreve.68.066401] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Indexed: 11/07/2022]
Abstract
We have calculated the radiative opacities of iron plasma in local thermodynamic equilibrium using a detailed term accounting model. The extensive atomic data are obtained by multiconfiguration Hartree-Fock (MCHF) method, with Breit-Pauli relativistic corrections. Extensive configuration interaction (CI) has been included based on LS coupling to obtain energy levels and the bound-bound transition cross sections. A detailed configuration accounting model is applied to evaluate the bound-free absorption cross sections. We simulate two experimental transmission spectra [G. Winhart et al., Phys. Rev. E 53, R1332 (1996); P. T. Springer et al., J. Quant. Spectrosc. Radiat. Transf. 58, 927 (1997)] to verify our calculation model, one is at a temperature of 22 eV and a density of 10(-2) g/cm(3) and the other is at a temperature of 20 eV and a lower density of 10(-4) g/cm(3). It is shown that the strong CI can effectively change the oscillator strengths in contrast to the single configuration HF method. For both of the two simulated transmission spectra good agreement is obtained between the present MCHF results and the experimental data. Spectrally resolved opacities and Planck and Rosseland mean opacities are also calculated. For the isothermal sequence of T=20 eV, when the density decreases from 10(-2) to 10(-5) g/cm(3), the linewidth also decreases so that the iron transition arrays show more discrete line structures and the linewidth becomes very important to the Rosseland mean opacity.
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Affiliation(s)
- Fengtao Jin
- Department of Applied Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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27
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Keiter PA, Drake RP, Perry TS, Robey HF, Remington BA, Iglesias CA, Wallace RJ, Knauer J. Observation of a hydrodynamically driven, radiative-precursor shock. PHYSICAL REVIEW LETTERS 2002; 89:165003. [PMID: 12398730 DOI: 10.1103/physrevlett.89.165003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2001] [Indexed: 05/24/2023]
Abstract
Observations of a radiative-precursor shock that evolves from a purely hydrodynamic system are presented. The radiative precursor is observed in low-density SiO2 aerogel foam using x-ray absorption spectroscopy. A plastic slab, shocked and accelerated by high-intensity laser irradiation, drives the shock which then produces the radiative precursor. The length and temperature profile of the radiative precursor are examined as the intensity of the laser is varied.
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28
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MacFarlane JJ, Bailey JE, Chandler GA, Deeney C, Douglas MR, Jobe D, Lake P, Nash TJ, Nielsen DS, Spielman RB, Wang P, Woodruff P. X-ray absorption spectroscopy measurements of thin foil heating by Z-pinch radiation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:046416. [PMID: 12443339 DOI: 10.1103/physreve.66.046416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2002] [Indexed: 05/24/2023]
Abstract
Absorption spectroscopy measurements of the time-dependent heating of thin foils exposed to intense z-pinch radiation sources are presented. These measurements and their analysis provide valuable benchmarks for, and insights into, the radiative heating of matter by x-ray sources. Z-pinch radiation sources with peak powers of up to 160 TW radiatively heated thin plastic-tamped aluminum foils to temperatures approximately 60 eV. The foils were located in open slots at the boundary of z-pinch hohlraums surrounding the pinch. Time-resolved Kalpha satellite absorption spectroscopy was used to measure the evolution of the Al ionization distribution, using a geometry in which the pinch served as the backlighter. The time-dependent pinch radius and x-ray power were monitored using framing camera, x-ray diode array, and bolometer measurements. A three-dimensional view factor code, within which one-dimensional (1D) radiation-hydrodynamics calculations were performed for each surface element in the view factor grid, was used to compute the incident and reemitted radiation flux distribution throughout the hohlraum and across the foil surface. Simulated absorption spectra were then generated by postprocessing radiation-hydrodynamics results for the foil heating using a 1D collisional-radiative code. Our simulated results were found to be in good general agreement with experimental x-ray spectra, indicating that the spectral measurements are consistent with independent measurements of the pinch power. We also discuss the sensitivity of our results to the spectrum of the radiation field incident on the foil, and the role of nonlocal thermodynamic equilibrium atomic kinetics in affecting the spectra.
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Affiliation(s)
- J J MacFarlane
- Prism Computational Sciences, 16 North Carroll Street, Suite 950, Madison, Wisconsin 53703, USA
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29
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Zeng J, Yuan J. Detailed-term-accounting approximation calculations of the radiative opacity of aluminum plasmas: a systematic study. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:016401. [PMID: 12241484 DOI: 10.1103/physreve.66.016401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2002] [Revised: 03/13/2002] [Indexed: 05/23/2023]
Abstract
The spectrally resolved radiative opacity and the Rosseland and Planck mean opacities are calculated by using the detailed-term-accounting approximation for aluminum plasmas with varieties of density and temperature. The results are presented along a 40 eV isothermal sequence, a 0.01 g/cm(3) isodense sequence, and a sequence with average ionization degree Z* approximately 7.13. Particular attention is given to the influence of the detailed treatment of spectral lines on the Rosseland mean opacity under different thermodynamic conditions. The results show that at densities of 0.004 g/cm(3) and higher, the opacities are not very sensitive to the spectral linewidth within a reasonable range. As examples, the Rosseland mean opacity, which is most sensitive to the detailed linewidth, at 40 eV and 0.004 g/cm(3) changes no more than 15%, when we change the electron impact spectral linewidth artificially by reducing it by 50% or increasing it twice, and at 40 eV and 0.1 g/cm(3) it changes less than 5%. For comparison, we also carried out calculations by using an average atom model. For the Rosseland mean opacities, the two models show quite large differences, in particular at low densities, while for the Planck mean opacities the results of the two models are much closer.
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Affiliation(s)
- Jiaolong Zeng
- Department of Applied Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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30
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Zeng J, Yuan J, Lu Q. Detailed-term-accounting-approximation calculations of the radiative opacity of laser-produced Al plasmas. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:066412. [PMID: 11736287 DOI: 10.1103/physreve.64.066412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2001] [Revised: 07/24/2001] [Indexed: 05/23/2023]
Abstract
An extensive configuration interaction (CI) scheme and the R-matrix method are combined to calculate the radiative opacity for laser-produced aluminum plasma in local thermodynamic equilibrium using the detailed-term-accounting (DTA) approximation. The CI scheme is used to obtain the absorption oscillator strengths of the electric dipole allowed transitions for evaluating the bound-bound absorption cross sections, and the R-matrix method is used to obtain the bound-free absorption (photoionization) cross sections. For an aluminum plasma at a temperature of 20 eV and the density of 0.01 g/cm(3), the Rosseland and Planck mean opacities are calculated to be 4184 and 24891 cm(2)/g, respectively, by integrating the spectrally resolved opacities with Rosseland and Planck weighting functions. The two mean opacities are also obtained by using the average atom model, and they are 22520 and 30402 cm(2)/g, respectively. The optical transmission from the photon energy of 70-250 eV, which was experimentally measured by Winhart et al. [G. Winhart et al. Phys. Rev. E 53, R1332 (1996)], is also calculated. Generally good agreement is found between our DTA and experimental transmission. Our theoretical result reproduces all structures shown in the experiment, whereas some of the structures near the higher energy edge did not show up in some other opacity models. These structures are attributed to the detailed treatment of the photoionization process.
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Affiliation(s)
- J Zeng
- Department of Applied Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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Zeng J, Jin F, Yuan J, Lu Q, Sun Y. Detailed-term-accounting-approximation simulation of x-ray transmission through laser-produced Al plasmas. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 62:7251-7257. [PMID: 11102083 DOI: 10.1103/physreve.62.7251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2000] [Revised: 07/14/2000] [Indexed: 05/23/2023]
Abstract
An extensive configuration interaction (CI) scheme and the R-matrix method are combined to calculate the x-ray transmission spectrum for high-power laser-produced Al plasmas in local thermodynamic equilibrium by using the detailed-term-accounting (DTA) approximation. All atomic parameters such as state levels and photoabsorption cross sections for different ionization stages are obtained by using the CI and R-matrix method. Special attention is given to the effects of autoionizing resonance broadening on the transmission. A large difference exists between the convergence of the results with and without taking account of autoionizing resonance broadening when the autoionization resonance broadening is the major broadening mechanism. This shows that autoionizing resonance widths of the K-shell excited states have large effects and should be considered to interpret the spectral-resolved transmission.
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Affiliation(s)
- J Zeng
- Department of Applied Physics, National University of Defense Technology, Changsha 410073, People's Republic of China
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Back CA, Bauer JD, Landen OL, Turner RE, Lasinski BF, Hammer JH, Rosen MD, Suter LJ, Hsing WH. Detailed measurements of a diffusive supersonic wave in a radiatively heated foam. PHYSICAL REVIEW LETTERS 2000; 84:274-277. [PMID: 11015889 DOI: 10.1103/physrevlett.84.274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/1999] [Indexed: 05/23/2023]
Abstract
We have made the first detailed measurements of a diffusive supersonic radiation wave in the laboratory. A 10 mg/cm(3) SiO2 foam is radiatively heated by the x-ray flux from a laser-irradiated hohlraum. The resulting radiation wave propagates axially through the optically thick foam and is measured via time-resolved x-ray imaging as it breaks out the far end. The data show that the radiation wave breaks out at the center prior to breaking out at the edges, indicating a significant curvature in the radiation front. This curvature is primarily due to energy loss into the walls surrounding the foam.
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Affiliation(s)
- CA Back
- Lawrence Livermore National Laboratory, L-21, P.O. Box 808, Livermore, California 94551, USA
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Aglitskiy Y, Lehecka T, Obenschain S, Bodner S, Pawley C, Gerber K, Sethian J, Brown CM, Seely J, Feldman U, Holland G. High-resolution monochromatic x-ray imaging system based on spherically bent crystals. APPLIED OPTICS 1998; 37:5253-5261. [PMID: 18286004 DOI: 10.1364/ao.37.005253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have developed an improved x-ray imaging system based on spherically curved crystals. It is designed and used for diagnostics of targets ablatively accelerated by the Nike KrF laser. A spherically curved quartz crystal (d = .?, R = mm) has been used to produce monochromatic backlit images with the He-like Si resonance line (1865 eV) as the source of radiation. The spatial resolution of the x-ray optical system is 1.7 mum in selected places and 2-3 mum over a larger area. Time-resolved backlit monochromatic images of polystyrene planar targets driven by the Nike facility have been obtained with a spatial resolution of 2.5 mum in selected places and 5 mum over the focal spot of the Nike laser.
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Beiersdorfer P, Osterheld AL, Decaux V, Widmann K. Observation of Lifetime-Limited X-Ray Linewidths in Cold Highly Charged Ions. PHYSICAL REVIEW LETTERS 1996; 77:5353-5356. [PMID: 10062782 DOI: 10.1103/physrevlett.77.5353] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Back CA, Kalantar DH, Kauffman RL, Lee RW, MacGowan BJ, Montgomery DS, Powers LV, Shepard TD, Stone GF, Suter LJ. Measurements of Electron Temperature by Spectroscopy in Hohlraum Targets. PHYSICAL REVIEW LETTERS 1996; 77:4350-4353. [PMID: 10062516 DOI: 10.1103/physrevlett.77.4350] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Perry TS, Springer PT, Fields DF, Bach DR, Serduke FJ, Iglesias CA, Rogers FJ, Nash JK, Chen MH, Wilson BG, Goldstein WH, Rozsynai B, Ward RA, Kilkenny JD, Doyas R, Back CA, Cauble R, Davidson SJ, Foster JM, Smith CC, Bar-Shalom A, Lee RW. Absorption experiments on x-ray-heated mid-Z constrained samples. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:5617-5631. [PMID: 9965749 DOI: 10.1103/physreve.54.5617] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Cauble R, Barbee TW, Celliers P, Decker C, London RA, Moreno JC, Trebes JE, Wan AS, Weber F. Simultaneous Measurement of Local Gain and Electron Density in X-ray Lasers. Science 1996; 273:1093-6. [PMID: 8688093 DOI: 10.1126/science.273.5278.1093] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
X-ray lasers (XRLs) have experimental average gains that are significantly less than calculated values and a persistently low level of spatial coherence. An XRL has been used both as an injected signal to a short XRL amplifier and as an interferometer beam to measure two-dimensional local gain and density profiles of the XRL plasma with a resolution near 1 micrometer. The measured local gain is in agreement with atomic models but is unexpectedly spatially inhomogeneous. This inhomogeneity is responsible for the low level of spatial coherence observed and helps explain the disparity between observed and simulated gains.
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Affiliation(s)
- R Cauble
- Lawrence Livermore National Laboratory, University of California, Livermore, CA 94550, USA
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Winhart G, Eidmann K, Iglesias CA, Bar-Shalom A. Measurements of extreme uv opacities in hot dense Al, Fe, and Ho. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:R1332-R1335. [PMID: 9964479 DOI: 10.1103/physreve.53.r1332] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Bauer JD, Back CA, Castor JI, Dykema PG, Hammel BA, Lee RW, Nash JK, Seely JF, Feldman U, Brown CM. Simulation and analysis of an x-ray-heated boron nitride foil. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:6736-6752. [PMID: 9964189 DOI: 10.1103/physreve.52.6736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Mostovych AN, Chan LY, Kearney KJ, Garren D, Iglesias CA, Klapisch M, Rogers FJ. Opacity of Dense, Cold, and Strongly Coupled Plasmas. PHYSICAL REVIEW LETTERS 1995; 75:1530-1533. [PMID: 10060321 DOI: 10.1103/physrevlett.75.1530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Barbee TW, Cauble R, Celliers P, Ciarlo D, Libby S, London RA, Matthews D, Mrowka S, Moreno JC, Ress D, Trebes JE, Wan AS, Weber F. Electron Density Measurements of High Density Plasmas Using Soft X-Ray Laser Interferometry. PHYSICAL REVIEW LETTERS 1995; 74:3991-3994. [PMID: 10058385 DOI: 10.1103/physrevlett.74.3991] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Moreno JC, Back CA, Cauble RC, Koch JA, Lee RW. Time-resolved density measurements of x-ray-heated Teflon foils using absorption spectroscopy. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:4897-4900. [PMID: 9963202 DOI: 10.1103/physreve.51.4897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Massen J, Tsakiris GD, Eidmann K, Földes IB, Löwer T, Sigel R, Witkowski S, Nishimura H, Endo T, Shiraga H, Takagi M, Kato Y, Nakai S. Supersonic radiative heat waves in low-density high-Z material. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 50:5130-5133. [PMID: 9962602 DOI: 10.1103/physreve.50.5130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Kauffman RL, Suter LJ, Darrow CB, Kilkenny JD, Kornblum HN, Montgomery DS, Phillion DW, Rosen MD, Theissen AR, Wallace RJ, Ze F. High temperatures in inertial confinement fusion radiation cavities heated with 0.35 microm light. PHYSICAL REVIEW LETTERS 1994; 73:2320-2323. [PMID: 10057030 DOI: 10.1103/physrevlett.73.2320] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Afshar-rad T, Desselberger M, Dunne M, Edwards J, Foster JM, Hoarty D, Jones MW, Rose SJ, Rosen PA, Taylor R, Willi O. Supersonic propagation of an ionization front in low density foam targets driven by thermal radiation. PHYSICAL REVIEW LETTERS 1994; 73:74-77. [PMID: 10056723 DOI: 10.1103/physrevlett.73.74] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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White VJ, Foster JM, Hansom JC, Rosen PA, Rose SJ. Measurements of radiation heat transport in germanium: Validationinebreak of an opacity model. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 49:R4803-R4806. [PMID: 9961940 DOI: 10.1103/physreve.49.r4803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Endo T, Shiraga H, Nishimura H, Fujishima A, Shigemori K, Kato Y, Nakai S, Yamanaka C. Experimental observation of transmission- and self-emission-type radiation transport in x-ray-produced plasmas. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 49:R1815-R1818. [PMID: 9961510 DOI: 10.1103/physreve.49.r1815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Abstract
An array of problems in astronomy, cosmology, and particle physics is dependent on our understanding of the evolution and structure of stars. Stellar structure and evolution, in turn, depend on how the nuclear energy generated in the stellar center is transported to the surface. Energy transport by photons is a primary transfer mechanism. Recent improvements in the calculation of the radiative properties of stellar matter have helped resolve several long-standing discrepancies between observations and the predictions of theoretical models.
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Wang P, MacFarlane JJ, Moses GA. Relativistic-configuration-interaction calculations of K alpha satellite properties for aluminum plasmas created by intense proton beams. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1993; 48:3934-3942. [PMID: 9961051 DOI: 10.1103/physreve.48.3934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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MacFarlane JJ, Wang P, Bailey J, Mehlhorn TA, Dukart RJ, Mancini RC. Analysis of K alpha line emission from aluminum plasmas created by intense proton beams. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1993; 47:2748-2758. [PMID: 9960307 DOI: 10.1103/physreve.47.2748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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