1
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MacDonald MJ, Liedahl DA, Brown GV, Åberg D, Cliche DT, Foord ME, Grabowski PE, Heeter RF, Hoarty DJ, London RA, Martin ME, Nilsen J, Patel MV, Scott HA, Shepherd R, Whitley HD, Widmann K. Quantifying electron temperature distributions from time-integrated x-ray emission spectra. Rev Sci Instrum 2022; 93:093517. [PMID: 36182496 DOI: 10.1063/5.0101571] [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: 06/01/2022] [Accepted: 08/16/2022] [Indexed: 06/16/2023]
Abstract
K-shell x-ray emission spectroscopy is a standard tool used to diagnose the plasma conditions created in high-energy-density physics experiments. In the simplest approach, the emissivity-weighted average temperature of the plasma can be extracted by fitting an emission spectrum to a single temperature condition. It is known, however, that a range of plasma conditions can contribute to the measured spectra due to a combination of the evolution of the sample and spatial gradients. In this work, we define a parameterized model of the temperature distribution and use Markov Chain Monte Carlo sampling of the input parameters, yielding uncertainties in the fit parameters to assess the uniqueness of the inferred temperature distribution. We present the analysis of time-integrated S and Fe x-ray spectroscopic data from the Orion laser facility and demonstrate that while fitting each spectral region to a single temperature yields two different temperatures, both spectra can be fit simultaneously with a single temperature distribution. We find that fitting both spectral regions together requires a maximum temperature of 1310-70 +90 eV with significant contributions from temperatures down to 200 eV.
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Affiliation(s)
- M J MacDonald
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - D Åberg
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - D T Cliche
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - M E Foord
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - P E Grabowski
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - D J Hoarty
- Directorate of Research and Applied Science, AWE Plc, Reading RG7 4PR, United Kingdom
| | - R A London
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - M E Martin
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - J Nilsen
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - M V Patel
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - H A Scott
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - R Shepherd
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - H D Whitley
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - K Widmann
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
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2
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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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3
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MacDonald MJ, Widmann K, Beiersdorfer P, Hell N, Hoarty DJ, Magee EW, Shah C, Shepherd R, Brown GV. Absolute throughput calibration of multiple spherical crystals for the Orion High-REsolution X-ray spectrometer (OHREX). Rev Sci Instrum 2021; 92:023509. [PMID: 33648146 DOI: 10.1063/5.0043683] [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: 01/10/2021] [Accepted: 01/28/2021] [Indexed: 06/12/2023]
Abstract
We present absolute throughput analysis of several crystals for the Orion High-REsolution X-ray (OHREX) imaging crystal spectrometer using ray tracing and experimental measurements. The OHREX spectrometer is a high-resolution x-ray spectrometer designed to measure spectral line shapes at the Orion laser facility. The spectrometer is fielded with up to two spherical crystals simultaneously covering two independent spectral ranges. Each crystal has a nominal radius of curvature of R = 67.2 cm and is fielded at a nominal Bragg angle of 51.3°. To cover different bands of interest, several different crystals are available, including Ge (111), KAP, and several cuts of quartz, whose resolving power λ/Δλ exceeds 10 000. The calibrated response of the available crystals has previously been reported from measurements at the EBIT-I electron beam ion trap at Lawrence Livermore National Laboratory. Here, we model the absolute throughput of each crystal using ray tracing and verify the results using experimental data for the quartz (101¯1) crystal.
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Affiliation(s)
- M J MacDonald
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - K Widmann
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Hoarty
- Directorate of Research and Applied Science, AWE plc, Reading RG7 4PR, United Kingdom
| | - E W Magee
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Shah
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Shepherd
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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4
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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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5
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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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6
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Culfa O, Tallents GJ, Rossall AK, Wagenaars E, Ridgers CP, Murphy CD, Dance RJ, Gray RJ, McKenna P, Brown CDR, James SF, Hoarty DJ, Booth N, Robinson APL, Lancaster KL, Pikuz SA, Faenov AY, Kampfer T, Schulze KS, Uschmann I, Woolsey NC. Plasma scale-length effects on electron energy spectra in high-irradiance laser plasmas. Phys Rev E 2016; 93:043201. [PMID: 27176413 DOI: 10.1103/physreve.93.043201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 06/05/2023]
Abstract
An analysis of an electron spectrometer used to characterize fast electrons generated by ultraintense (10^{20}Wcm^{-2}) laser interaction with a preformed plasma of scale length measured by shadowgraphy is presented. The effects of fringing magnetic fields on the electron spectral measurements and the accuracy of density scale-length measurements are evaluated. 2D EPOCH PIC code simulations are found to be in agreement with measurements of the electron energy spectra showing that laser filamentation in plasma preformed by a prepulse is important with longer plasma scale lengths (>8 μm).
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Affiliation(s)
- O Culfa
- Department of Physics, Karamanoglu MehmetBey University, Karaman, Turkey
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - G J Tallents
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - A K Rossall
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - E Wagenaars
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - C P Ridgers
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - C D Murphy
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - R J Dance
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
| | - R J Gray
- SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - P McKenna
- SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - C D R Brown
- AWE, Aldermaston, Reading, Berkshire RG7 4PR, United Kingdom
| | - S F James
- AWE, Aldermaston, Reading, Berkshire RG7 4PR, United Kingdom
| | - D J Hoarty
- AWE, Aldermaston, Reading, Berkshire RG7 4PR, United Kingdom
| | - N Booth
- CLF, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - A P L Robinson
- CLF, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - K L Lancaster
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
- CLF, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - S A Pikuz
- Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412, Russia
| | - A Ya Faenov
- Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412, Russia
- Osaka University, Suita, Osaka 656-0871, Japan
| | - T Kampfer
- Friedrich Schiller University of Jena, D-07743 Jena, Germany
| | - K S Schulze
- Friedrich Schiller University of Jena, D-07743 Jena, Germany
| | - I Uschmann
- Friedrich Schiller University of Jena, D-07743 Jena, Germany
| | - N C Woolsey
- York Plasma Institute, The Department of Physics, The University of York, York YO10 5DD, United Kingdom
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7
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Steel AB, Dunn J, Emig J, Beiersdorfer P, Brown GV, Shepherd R, Marley EV, Hoarty DJ. Development of a ten inch manipulators-based, flexible, broadband two-crystal spectrometer. Rev Sci Instrum 2014; 85:11D610. [PMID: 25430186 DOI: 10.1063/1.4890671] [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: 06/04/2023]
Abstract
We have developed and implemented a broadband X-ray spectrometer with a variable energy range for use at the Atomic Weapons Establishment's Orion Laser. The spectrometer covers an energy bandwidth of ∼1-2 keV using two independently mounted, movable Bragg diffraction crystals. Using combinations of cesium hydrogen pthlate, ammonium dihydrogen phosphate, and pentaerythritol crystals, spectra covering the 1.4-2.5, 1.85-3.15, or 3.55-5.1 keV energy bands have been measured. Image plate is used for detection owing to its high dynamic range. Background signals caused by high energy X-rays and particles commonly produced in high energy laser experiments are reduced by a series of tantalum baffles and filters installed between the source and crystal and also between the crystals and detector.
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Affiliation(s)
- A B Steel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Dunn
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Emig
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Shepherd
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E V Marley
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Hoarty
- Atomic Weapons Establishment, Aldermaston, United Kingdom
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8
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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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9
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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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10
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Sarri G, Cecchetti CA, Jung R, Hobbs P, James S, Lockyear J, Stevenson RM, Doria D, Hoarty DJ, Willi O, Borghesi M. Spatially resolved measurements of laser filamentation in long scale length underdense plasmas with and without beam smoothing. Phys Rev Lett 2011; 106:095001. [PMID: 21405630 DOI: 10.1103/physrevlett.106.095001] [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: 01/07/2010] [Indexed: 05/30/2023]
Abstract
The onset of filamentation, following the interaction of a relatively long (τ(L)≃1 ns) and intense (I(L)≃5×10(14) W/cm(2)) laser pulse with a neopentane filled gas bag target, has been experimentally studied via the proton radiography technique, in conditions of direct relevance to the indirect drive inertial confinement fusion scheme. The density gradients associated with filamentation onset have been spatially resolved yielding direct and unambiguous evidence of filament formation and quantitative information about the filamentation mechanism in agreement with previous theoretical modelings. Experimental data confirm that, once spatially smoothed laser beams are used, filamentation is not a relevant phenomenon during the heating laser beams propagation through typical hohlraum gas fills.
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Affiliation(s)
- G Sarri
- School of Mathematics and Physics, The Queen's University of Belfast, United Kingdom
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11
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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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12
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Foster JM, Hoarty DJ, Smith CC, Rosen PA, Davidson SJ, Rose SJ, Perry TS, Serduke FJ. L-shell absorption spectrum of an open-M-shell germanium plasma: Comparison of experimental data with a detailed configuration-accounting calculation. Phys Rev Lett 1991; 67:3255-3258. [PMID: 10044686 DOI: 10.1103/physrevlett.67.3255] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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