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Hell N, Beiersdorfer P, Brown GV, Lockard TE, Magee EW, Shepherd R, Hoarty DJ, Brown CRD, Hill MP, Hobbs LMR, James SF, Lynch C, Caughey TA. Recent enhancements in the performance of the Orion high-resolution x-ray spectrometers. Rev Sci Instrum 2021; 92:043507. [PMID: 34243402 DOI: 10.1063/5.0043804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/17/2021] [Indexed: 06/13/2023]
Abstract
During the past few years, the Orion high-resolution x-ray spectrometers have been successful tools for measuring x-ray spectra from plasmas generated in the Orion laser facility. Duplicate spectrometers also operate successfully at the Livermore EBIT-I and SuperEBIT electron beam ion traps for measuring x-ray polarization. We have recently implemented very high-quality, optically bonded, spherically bent quartz crystals to remove the structure in the x-ray image that had been observed in earlier measurements. The structure had been caused by focusing defects and limited the accuracy of our measurements. We present before and after images that show a drastic improvement. We, furthermore, have implemented a spherically bent potassium acid phthalate (KAP) crystal on one of our spectrometers. The KAP crystal was prepared in a similar fashion, and we present measurements of the N Ly-β and Ne Lyβ lines taken in first- and second-order reflections at 600 and 1200 eV, respectively. These measurements confirm that KAP crystals can be produced at a quality suitable for extending the spectral coverage to wavelengths longer than those accessible by different quartz crystals, especially those that cover the astrophysically important lines of iron.
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Affiliation(s)
- N Hell
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Beiersdorfer
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T E Lockard
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E W Magee
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Shepherd
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Hoarty
- Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom
| | - C R D Brown
- Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom
| | - M P Hill
- Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom
| | - L M R Hobbs
- Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom
| | - S F James
- Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom
| | - C Lynch
- Inrad Optics, Northvale, New Jersey 07647, USA
| | - T A Caughey
- Inrad Optics, Northvale, New Jersey 07647, USA
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2
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Beiersdorfer P, Magee EW, Brown GV, Hell N, McKelvey A, Shepherd R, Hoarty DJ, Brown CRD, Hill MP, Hobbs LMR, James SF, Wilson L. High resolution, high signal-to-noise crystal spectrometer for measurements of line shifts in high-density plasmas. Rev Sci Instrum 2018; 89:10F120. [PMID: 30399793 DOI: 10.1063/1.5035303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
The Orion high-resolution x-ray (OHREX) spectrometer has been a successful tool for measuring the shapes of density-broadened spectral lines produced in short-pulse heated plasmas at the Orion laser facility. We have recently outfitted the instrument with a charge-couple device (CCD) camera, which greatly increased the accuracy with which we can perform line-shift measurements. Because OHREX is located on the outside of the Orion target chamber, no provisions for the shielding of electromagnetic pulses are required. With the CCD, we obtained a higher signal-to-noise ratio than we previously obtained with an image-plate detector. This allowed us to observe structure in the image produced by the diffraction from the two OHREX crystals, which was highly reproducible from shot to shot. This structure will ultimately limit the accuracy of our spectroscopic measurements.
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Affiliation(s)
- P Beiersdorfer
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E W Magee
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Hell
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A McKelvey
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Shepherd
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Hoarty
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - C R D Brown
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - M P Hill
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - L M R Hobbs
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - S F James
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - L Wilson
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
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3
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Johns HM, Lanier NE, Kline JL, Fontes CJ, Perry TS, Fryer CL, Brown CRD, Morton JW, Hager JD, Sherrill ME. Atomic physics modeling of transmission spectra of Sc-doped aerogel foams to support OMEGA experiments. Rev Sci Instrum 2016; 87:11E337. [PMID: 27910339 DOI: 10.1063/1.4962195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present synthetic transmission spectra generated with PrismSPECT utilizing both the ATBASE model and the Los Alamos opacity library (OPLIB) to evaluate whether an alternative choice in atomic data will impact modeling of experimental data from radiation transport experiments using Sc-doped aerogel foams (ScSi6O12 at 75 mg/cm3 density). We have determined that in the 50-200 eV Te range there is a significant difference in the 1s-3p spectra, especially below 100 eV, and for Te = 200 eV above 5000 eV in photon energy. Examining synthetic spectra generated using OPLIB with 300 resolving power reveals spectral sensitivity to Te changes of ∼3 eV.
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Affiliation(s)
- H M Johns
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - N E Lanier
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - J L Kline
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - C J Fontes
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - T S Perry
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - C L Fryer
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - C R D Brown
- AWE Aldermaston, Berkshire, Reading RG7 4PR, United Kingdom
| | - J W Morton
- AWE Aldermaston, Berkshire, Reading RG7 4PR, United Kingdom
| | - J D Hager
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
| | - M E Sherrill
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87544, USA
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4
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Beiersdorfer P, Magee EW, Brown GV, Chen H, Emig J, Hell N, Bitter M, Hill KW, Allan P, Brown CRD, Hill MP, Hoarty DJ, Hobbs LMR, James SF. Lineshape spectroscopy with a very high resolution, very high signal-to-noise crystal spectrometer. Rev Sci Instrum 2016; 87:063501. [PMID: 27370448 DOI: 10.1063/1.4952748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/14/2016] [Indexed: 06/06/2023]
Abstract
We have developed a high-resolution x-ray spectrometer for measuring the shapes of spectral lines produced from laser-irradiated targets on the Orion laser facility. The instrument utilizes a spherically bent crystal geometry to spatially focus and spectrally analyze photons from foil or microdot targets. The high photon collection efficiency resulting from its imaging properties allows the instrument to be mounted outside the Orion chamber, where it is far less sensitive to particles, hard x-rays, or electromagnetic pulses than instruments housed close to the target chamber center in ten-inch manipulators. Moreover, Bragg angles above 50° are possible, which provide greatly improved spectral resolution compared to radially viewing, near grazing-incidence crystal spectrometers. These properties make the new instrument an ideal lineshape diagnostic for determining plasma temperature and density. We describe its calibration on the Livermore electron beam ion trap facility and present spectral data of the K-shell emission from highly charged sulfur produced by long-pulse as well as short-pulse beams on the Orion laser in the United Kingdom.
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Affiliation(s)
- P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E W Magee
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - H Chen
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Emig
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Bitter
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - K W Hill
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - P Allan
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - C R D Brown
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - M P Hill
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - D J Hoarty
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - L M R Hobbs
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - S F James
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
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5
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Vinko SM, Ciricosta O, Preston TR, Rackstraw DS, Brown CRD, Burian T, Chalupský J, Cho BI, Chung HK, Engelhorn K, Falcone RW, Fiokovinini R, Hájková V, Heimann PA, Juha L, Lee HJ, Lee RW, Messerschmidt M, Nagler B, Schlotter W, Turner JJ, Vysin L, Zastrau U, Wark JS. Investigation of femtosecond collisional ionization rates in a solid-density aluminium plasma. Nat Commun 2015; 6:6397. [PMID: 25731816 DOI: 10.1038/ncomms7397] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/26/2015] [Indexed: 11/09/2022] Open
Abstract
The rate at which atoms and ions within a plasma are further ionized by collisions with the free electrons is a fundamental parameter that dictates the dynamics of plasma systems at intermediate and high densities. While collision rates are well known experimentally in a few dilute systems, similar measurements for nonideal plasmas at densities approaching or exceeding those of solids remain elusive. Here we describe a spectroscopic method to study collision rates in solid-density aluminium plasmas created and diagnosed using the Linac Coherent light Source free-electron X-ray laser, tuned to specific interaction pathways around the absorption edges of ionic charge states. We estimate the rate of collisional ionization in solid-density aluminium plasmas at temperatures ~30 eV to be several times higher than that predicted by standard semiempirical models.
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Affiliation(s)
- S M Vinko
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - O Ciricosta
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - T R Preston
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - D S Rackstraw
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - C R D Brown
- Department of Plasma Physics, AWE Aldermaston, Reading RG7 4PR, UK
| | - T Burian
- Institute of Physics ASCR, Na Slovance 2, Prague 8 18221, Czech Republic
| | - J Chalupský
- Institute of Physics ASCR, Na Slovance 2, Prague 8 18221, Czech Republic
| | - B I Cho
- 1] Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712, Korea [2] Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - H-K Chung
- Atomic and Molecular Data Unit, Nuclear Data Section, IAEA, PO Box 100, Vienna A-1400, Austria
| | - K Engelhorn
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, California 94720, USA
| | - R W Falcone
- 1] Lawrence Berkeley National Laboratory, 1 Cyclotron Road, California 94720, USA [2] Department of Physics, University of California, Berkeley, California 94720, USA
| | - R Fiokovinini
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - V Hájková
- Institute of Physics ASCR, Na Slovance 2, Prague 8 18221, Czech Republic
| | - P A Heimann
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - L Juha
- Institute of Physics ASCR, Na Slovance 2, Prague 8 18221, Czech Republic
| | - H J Lee
- 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
| | - M Messerschmidt
- National Science Foundation BioXFEL Science and Technology Center, 700 Ellicott Street, Buffalo, New York 14203, USA
| | - B Nagler
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - W Schlotter
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - J J Turner
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - L Vysin
- Institute of Physics ASCR, Na Slovance 2, Prague 8 18221, Czech Republic
| | - U Zastrau
- IOQ, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, Jena 07743, Germany
| | - J S Wark
- Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
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6
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Hoarty DJ, Allan P, James SF, Brown CRD, Hobbs LMR, Hill MP, Harris JWO, Morton J, Brookes MG, Shepherd R, Dunn J, Chen H, Von Marley E, Beiersdorfer P, Chung HK, Lee RW, Brown G, Emig J. Observations of the effect of ionization-potential depression in hot dense plasma. Phys Rev Lett 2013; 110:265003. [PMID: 23848885 DOI: 10.1103/physrevlett.110.265003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Indexed: 06/02/2023]
Abstract
The newly commissioned Orion laser system has been used to study dense plasmas created by a combination of short pulse laser heating and compression by laser driven shocks. Thus the plasma density was systematically varied between 1 and 10 g/cc by using aluminum samples buried in plastic foils or diamond sheets. The aluminum was heated to electron temperatures between 500 and 700 eV allowing the plasma conditions to be diagnosed by K-shell emission spectroscopy. The K-shell spectra show the effect of the ionization potential depression as a function of density. The data are compared to simulated spectra which account for the change in the ionization potential by the commonly used Stewart and Pyatt prescription and an alternative due to Ecker and Kröll suggested by recent x-ray free-electron laser experiments. The experimental data are in closer agreement with simulations using the model of Stewart and Pyatt.
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Affiliation(s)
- D J Hoarty
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
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7
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Cho BI, Engelhorn K, Vinko SM, Chung HK, Ciricosta O, Rackstraw DS, Falcone RW, Brown CRD, Burian T, Chalupský J, Graves C, Hájková V, Higginbotham A, Juha L, Krzywinski J, Lee HJ, Messersmidt M, Murphy C, Ping Y, Rohringer N, Scherz A, Schlotter W, Toleikis S, Turner JJ, Vysin L, Wang T, Wu B, Zastrau U, Zhu D, Lee RW, Nagler B, Wark JS, Heimann PA. Resonant Kα spectroscopy of solid-density aluminum plasmas. Phys Rev Lett 2012; 109:245003. [PMID: 23368333 DOI: 10.1103/physrevlett.109.245003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Indexed: 06/01/2023]
Abstract
The x-ray intensities made available by x-ray free electron lasers (FEL) open up new x-ray matter interaction channels not accessible with previous sources. We report here on the resonant generation of Kα emission, that is to say the production of copious Kα radiation by tuning the x-ray FEL pulse to photon energies below that of the K edge of a solid aluminum sample. The sequential absorption of multiple photons in the same atom during the 80 fs pulse, with photons creating L-shell holes and then one resonantly exciting a K-shell electron into one of these holes, opens up a channel for the Kα production, as well as the absorption of further photons. We demonstrate rich spectra of such channels, and investigate the emission produced by tuning the FEL energy to the K-L transitions of those highly charged ions that have transition energies below the K edge of the cold material. The spectra are sensitive to x-ray intensity dependent opacity effects, with ions containing L-shell holes readily reabsorbing the Kα radiation.
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Affiliation(s)
- B I Cho
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, California 94720, USA
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8
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White TG, Vorberger J, Brown CRD, Crowley BJB, Davis P, Glenzer SH, Harris JWO, Hochhaus DC, Le Pape S, Ma T, Murphy CD, Neumayer P, Pattison LK, Richardson S, Gericke DO, Gregori G. Observation of inhibited electron-ion coupling in strongly heated graphite. Sci Rep 2012. [PMID: 23189238 PMCID: PMC3506979 DOI: 10.1038/srep00889] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Creating non-equilibrium states of matter with highly unequal electron and lattice temperatures (T(ele)≠T(ion)) allows unsurpassed insight into the dynamic coupling between electrons and ions through time-resolved energy relaxation measurements. Recent studies on low-temperature laser-heated graphite suggest a complex energy exchange when compared to other materials. To avoid problems related to surface preparation, crystal quality and poor understanding of the energy deposition and transport mechanisms, we apply a different energy deposition mechanism, via laser-accelerated protons, to isochorically and non-radiatively heat macroscopic graphite samples up to temperatures close to the melting threshold. Using time-resolved x ray diffraction, we show clear evidence of a very small electron-ion energy transfer, yielding approximately three times longer relaxation times than previously reported. This is indicative of the existence of an energy transfer bottleneck in non-equilibrium warm dense matter.
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Affiliation(s)
- T G White
- University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK.
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9
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Bentley CD, Edwards RD, Andrew JE, James SF, Gardner MD, Comley AJ, Vaughan K, Horsfield CJ, Rubery MS, Rothman SD, Daykin S, Masoero SJ, Palmer JB, Meadowcroft AL, Williams BM, Gumbrell ET, Fyrth JD, Brown CRD, Hill MP, Oades K, Wright MJ, Hood BA, Kemshall P. ORION laser target diagnostics. Rev Sci Instrum 2012; 83:10D732. [PMID: 23126904 DOI: 10.1063/1.4748850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.
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Affiliation(s)
- C D Bentley
- Plasma Physics Department, Atomic Weapons Establishment, Aldermaston, Reading, Berkshire, England, UK.
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10
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Ciricosta O, Vinko SM, Chung HK, Cho BI, Brown CRD, Burian T, Chalupský J, Engelhorn K, Falcone RW, Graves C, Hájková V, Higginbotham A, Juha L, Krzywinski J, Lee HJ, Messerschmidt M, Murphy CD, Ping Y, Rackstraw DS, Scherz A, Schlotter W, Toleikis S, Turner JJ, Vysin L, Wang T, Wu B, Zastrau U, Zhu D, Lee RW, Heimann P, Nagler B, Wark JS. Direct measurements of the ionization potential depression in a dense plasma. Phys Rev Lett 2012; 109:065002. [PMID: 23006275 DOI: 10.1103/physrevlett.109.065002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Indexed: 06/01/2023]
Abstract
We have used the Linac Coherent Light Source to generate solid-density aluminum plasmas at temperatures of up to 180 eV. By varying the photon energy of the x rays that both create and probe the plasma, and observing the K-α fluorescence, we can directly measure the position of the K edge of the highly charged ions within the system. The results are found to disagree with the predictions of the extensively used Stewart-Pyatt model, but are consistent with the earlier model of Ecker and Kröll, which predicts significantly greater depression of the ionization potential.
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Affiliation(s)
- O Ciricosta
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, United Kingdom
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11
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Brown CRD, Hoarty DJ, James SF, Swatton D, Hughes SJ, Morton JW, Guymer TM, Hill MP, Chapman DA, Andrew JE, Comley AJ, Shepherd R, Dunn J, Chen H, Schneider M, Brown G, Beiersdorfer P, Emig J. Measurements of electron transport in foils irradiated with a picosecond time scale laser pulse. Phys Rev Lett 2011; 106:185003. [PMID: 21635097 DOI: 10.1103/physrevlett.106.185003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 11/19/2010] [Indexed: 05/30/2023]
Abstract
The heating of solid foils by a picosecond time scale laser pulse has been studied by using x-ray emission spectroscopy. The target material was plastic foil with a buried layer of a spectroscopic tracer material. The laser pulse length was either 0.5 or 2 ps, which resulted in a laser irradiance that varied over the range 10(16)-10(19) W/cm(2). Time-resolved measurements of the buried layer emission spectra using an ultrafast x-ray streak camera were used to infer the density and temperature conditions as a function of laser parameters and depth of the buried layer. Comparison of the data to different models of electron transport showed that they are consistent with a model of electron transport that predicts the bulk of the target heating is due to return currents.
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Affiliation(s)
- C R D Brown
- Directorate Science and Technology, AWE Aldermaston, Reading, United Kingdom
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12
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Hoarty DJ, James SF, Brown CRD, Williams BM, Guymer T, Hill M, Morton J, Chapman D, Shepherd R, Dunn J, Brown G, Schneider M, Beiersdorfer P, Chung HK, Harris JWO, Upcraft L, Smith CC, Lee RW. High temperature, high density opacity measurements using short pulse lasers. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/244/1/012002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Kritcher AL, Neumayer P, Brown CRD, Davis P, Döppner T, Falcone RW, Gericke DO, Gregori G, Holst B, Landen OL, Lee HJ, Morse EC, Pelka A, Redmer R, Roth M, Vorberger J, Wünsch K, Glenzer SH. Measurements of ionic structure in shock compressed lithium hydride from ultrafast x-ray Thomson scattering. Phys Rev Lett 2009; 103:245004. [PMID: 20366206 DOI: 10.1103/physrevlett.103.245004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Indexed: 05/29/2023]
Abstract
We present the first ultrafast temporally, spectrally, and angularly resolved x-ray scattering measurements from shock-compressed matter. The experimental spectra yield the absolute elastic and inelastic scattering intensities from the measured density of free electrons. Laser-compressed lithium-hydride samples are well characterized by inelastic Compton and plasmon scattering of a K-alpha x-ray probe providing independent measurements of temperature and density. The data show excellent agreement with the total intensity and structure when using the two-species form factor and accounting for the screening of ion-ion interactions.
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Affiliation(s)
- A L Kritcher
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551, USA
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Kugland NL, Gregori G, Bandyopadhyay S, Brenner CM, Brown CRD, Constantin C, Glenzer SH, Khattak FY, Kritcher AL, Niemann C, Otten A, Pasley J, Pelka A, Roth M, Spindloe C, Riley D. Evolution of elastic x-ray scattering in laser-shocked warm dense lithium. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 80:066406. [PMID: 20365285 DOI: 10.1103/physreve.80.066406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Indexed: 05/29/2023]
Abstract
We have studied the dynamics of warm dense Li with near-elastic x-ray scattering. Li foils were heated and compressed using shock waves driven by 4-ns-long laser pulses. Separate 1-ns-long laser pulses were used to generate a bright source of 2.96 keV Cl Ly- alpha photons for x-ray scattering, and the spectrum of scattered photons was recorded at a scattering angle of 120 degrees using a highly oriented pyrolytic graphite crystal operated in the von Hamos geometry. A variable delay between the heater and backlighter laser beams measured the scattering time evolution. Comparison with radiation-hydrodynamics simulations shows that the plasma is highly coupled during the first several nanoseconds, then relaxes to a moderate coupling state at later times. Near-elastic scattering amplitudes have been successfully simulated using the screened one-component plasma model. Our main finding is that the near-elastic scattering amplitudes are quite sensitive to the mean ionization state Z[over ] and by extension to the choice of ionization model in the radiation-hydrodynamics simulations used to predict plasma properties within the shocked Li.
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Affiliation(s)
- N L Kugland
- Physics Department, University of California-Los Angeles, Los Angeles, California 90095, USA
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Barbrel B, Koenig M, Benuzzi-Mounaix A, Brambrink E, Brown CRD, Gericke DO, Nagler B, Rabec le Gloahec M, Riley D, Spindloe C, Vinko SM, Vorberger J, Wark J, Wünsch K, Gregori G. Measurement of short-range correlations in shock-compressed plastic by short-pulse x-ray scattering. Phys Rev Lett 2009; 102:165004. [PMID: 19518720 DOI: 10.1103/physrevlett.102.165004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Indexed: 05/27/2023]
Abstract
We have performed short-pulse x-ray scattering measurements on laser-driven shock-compressed plastic samples in the warm dense matter regime, providing instantaneous snapshots of the system evolution. Time-resolved and angularly resolved scattered spectra sensitive to the correlation effects in the plasma show the appearance of short-range order within a few interionic separations. Comparison with radiation-hydrodynamic simulations indicates that the shocked plastic is compressed with a temperature of a few electron volts. These results are important for the understanding of the thermodynamic behavior of strongly correlated matter for conditions relevant to both laboratory astrophysics and inertial confinement fusion research.
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Affiliation(s)
- B Barbrel
- Laboratoire pour l'Utilisation de Lasers Intenses, UMR7605, CNRS CEA, Université Paris VI Ecole Polytechnique, 91128 Palaiseau Cedex, France
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