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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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Stierhof J, Kühn S, Winter M, Micke P, Steinbrügge R, Shah C, Hell N, Bissinger M, Hirsch M, Ballhausen R, Lang M, Gräfe C, Wipf S, Cumbee R, Betancourt-Martinez GL, Park S, Niskanen J, Chung M, Porter FS, Stöhlker T, Pfeifer T, Brown GV, Bernitt S, Hansmann P, Wilms J, Crespo López-Urrutia JR, Leutenegger MA. A new benchmark of soft X-ray transition energies of Ne , CO 2 , and SF 6 : paving a pathway towards ppm accuracy. Eur Phys J D At Mol Opt Phys 2022; 76:38. [PMID: 35273463 PMCID: PMC8888507 DOI: 10.1140/epjd/s10053-022-00355-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/23/2022] [Indexed: 06/14/2023]
Abstract
ABSTRACT A key requirement for the correct interpretation of high-resolution X-ray spectra is that transition energies are known with high accuracy and precision. We investigate the K-shell features of Ne , CO 2 , and SF 6 gases, by measuring their photo ion-yield spectra at the BESSY II synchrotron facility simultaneously with the 1s-np fluorescence emission of He-like ions produced in the Polar-X EBIT. Accurate ab initio calculations of transitions in these ions provide the basis of the calibration. While the CO 2 result agrees well with previous measurements, the SF 6 spectrum appears shifted by ∼ 0.5 eV, about twice the uncertainty of the earlier results. Our result for Ne shows a large departure from earlier results, but may suffer from larger systematic effects than our other measurements. The molecular spectra agree well with our results of time-dependent density functional theory. We find that the statistical uncertainty allows calibrations in the desired range of 1-10 meV, however, systematic contributions still limit the uncertainty to ∼ 40-100 meV, mainly due to the temporal stability of the monochromator energy scale. Combining our absolute calibration technique with a relative energy calibration technique such as photoelectron energy spectroscopy will be necessary to realize its full potential of achieving uncertainties as low as 1-10 meV.
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Affiliation(s)
- J. Stierhof
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | - S. Kühn
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - M. Winter
- Institute of Theoretical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 7/B2, 91058 Erlangen, Germany
- CNRS, Institut NEEL, Université Grenoble Alpes, CNRS, Institut NEEL, 25 rue des Martyrs BP 166, 38042 Grenoble Cedex 9, France
| | - P. Micke
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
- CERN, 1211 Geneva 23, Switzerland
| | - R. Steinbrügge
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - C. Shah
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd., Greenbelt, MD 20771 USA
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
| | - N. Hell
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
| | - M. Bissinger
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | - M. Hirsch
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | - R. Ballhausen
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | - M. Lang
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | - C. Gräfe
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | - S. Wipf
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - R. Cumbee
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd., Greenbelt, MD 20771 USA
- Department of Astronomy, University of Maryland, College Park, MD 20742 USA
| | - G. L. Betancourt-Martinez
- Institut de Recherche en Astrophysique et Planétologie, 9, avenue du Colonel Roche BP 44346, 31028 Toulouse Cedex 4, France
| | - S. Park
- Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, South Korea
| | - J. Niskanen
- Institute for Methods and Instrumentation in Synchrotron Radiation Research G-ISRR, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - M. Chung
- Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan, South Korea
| | - F. S. Porter
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd., Greenbelt, MD 20771 USA
| | - T. Stöhlker
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - T. Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - G. V. Brown
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 USA
| | - S. Bernitt
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - P. Hansmann
- Institute of Theoretical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 7/B2, 91058 Erlangen, Germany
| | - J. Wilms
- Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
| | | | - M. A. Leutenegger
- NASA Goddard Space Flight Center, 8800 Greenbelt Rd., Greenbelt, MD 20771 USA
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Eckart ME, Beiersdorfer P, Brown GV, Den Hartog DJ, Hell N, Kelley RL, Kilbourne CA, Magee EW, Mangoba AEY, Nornberg MD, Porter FS, Reusch LM, Wallace JP. Microcalorimeter measurement of x-ray spectra from a high-temperature magnetically confined plasma. Rev Sci Instrum 2021; 92:063520. [PMID: 34243585 DOI: 10.1063/5.0043980] [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: 01/12/2021] [Accepted: 04/29/2021] [Indexed: 06/13/2023]
Abstract
A NASA-built x-ray microcalorimeter spectrometer has been installed on the MST facility at the Wisconsin Plasma Physics Laboratory and has recorded x-ray photons emitted by impurity ions of aluminum in a majority deuterium plasma. Much of the x-ray microcalorimeter development has been driven by the needs of astrophysics missions, where imaging arrays with few-eV spectral resolution are required. The goal of our project is to adapt these single-photon-counting microcalorimeters for magnetic fusion energy research and demonstrate the value of such measurements for fusion science. Microcalorimeter spectrometers combine the best characteristics of the x-ray instrumentation currently available on fusion devices: high spectral resolution similar to an x-ray crystal spectrometer and the broadband coverage of an x-ray pulse height analysis system. Fusion experiments are increasingly employing high-Z plasma-facing components and require measurement of the concentration of all impurity ion species in the plasma. This diagnostic has the capability to satisfy this need for multi-species impurity ion data and will also contribute to measurements of impurity ion temperature and flow velocity, Zeff, and electron density. Here, we introduce x-ray microcalorimeter detectors and discuss the diagnostic capability for magnetic fusion energy experiments. We describe our experimental setup and spectrometer operation approach at MST, and we present the results from an initial measurement campaign.
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Affiliation(s)
- M E Eckart
- 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
| | - D J Den Hartog
- Wisconsin Plasma Physics Laboratory, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - N Hell
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R L Kelley
- X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - C A Kilbourne
- X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - E W Magee
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - A-E Y Mangoba
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M D Nornberg
- Wisconsin Plasma Physics Laboratory, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - F S Porter
- X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - L M Reusch
- Wisconsin Plasma Physics Laboratory, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - J P Wallace
- Wisconsin Plasma Physics Laboratory, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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4
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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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5
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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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6
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Leutenegger MA, Kühn S, Micke P, Steinbrügge R, Stierhof J, Shah C, Hell N, Bissinger M, Hirsch M, Ballhausen R, Lang M, Gräfe C, Wipf S, Cumbee R, Betancourt-Martinez GL, Park S, Yerokhin VA, Surzhykov A, Stolte WC, Niskanen J, Chung M, Porter FS, Stöhlker T, Pfeifer T, Wilms J, Brown GV, Crespo López-Urrutia JR, Bernitt S. High-Precision Determination of Oxygen K_{α} Transition Energy Excludes Incongruent Motion of Interstellar Oxygen. Phys Rev Lett 2020; 125:243001. [PMID: 33412031 DOI: 10.1103/physrevlett.125.243001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 10/19/2020] [Accepted: 10/30/2020] [Indexed: 06/12/2023]
Abstract
We demonstrate a widely applicable technique to absolutely calibrate the energy scale of x-ray spectra with experimentally well-known and accurately calculable transitions of highly charged ions, allowing us to measure the K-shell Rydberg spectrum of molecular O_{2} with 8 meV uncertainty. We reveal a systematic ∼450 meV shift from previous literature values, and settle an extraordinary discrepancy between astrophysical and laboratory measurements of neutral atomic oxygen, the latter being calibrated against the aforementioned O_{2} literature values. Because of the widespread use of such, now deprecated, references, our method impacts on many branches of x-ray absorption spectroscopy. Moreover, it potentially reduces absolute uncertainties there to below the meV level.
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Affiliation(s)
- M A Leutenegger
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA
| | - S Kühn
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - P Micke
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - R Steinbrügge
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - J Stierhof
- Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany
| | - C Shah
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - N Hell
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - M Bissinger
- Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Strasse 1, 91058 Erlangen, Germany
| | - M Hirsch
- Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany
| | - R Ballhausen
- Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany
| | - M Lang
- Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany
| | - C Gräfe
- Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany
| | - S Wipf
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - R Cumbee
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA
- Department of Astronomy, University of Maryland, College Park, Maryland 20742, USA
| | - G L Betancourt-Martinez
- Institut de Recherche en Astrophysique et Planétologie, 9, avenue du Colonel Roche BP 44346, 31028 Toulouse Cedex 4, France
| | - S Park
- Ulsan National Institute of Science and Technology, 50 UNIST-gil, 44919 Ulsan, Republic of Korea
| | - V A Yerokhin
- Peter the Great St. Petersburg Polytechnic University, 195251 St. Petersburg, Russia
| | - A Surzhykov
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
- Institut für Mathematische Physik, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - W C Stolte
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J Niskanen
- Institute for Methods and Instrumentation in Synchrotron Radiation Research G-ISRR, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Department of Physics and Astronomy, University of Turku, FI-20014 Turun Yliopisto, Finland
| | - M Chung
- Ulsan National Institute of Science and Technology, 50 UNIST-gil, 44919 Ulsan, Republic of Korea
| | - F S Porter
- NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA
| | - T Stöhlker
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - T Pfeifer
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - J Wilms
- Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstrasse 7, 96049 Bamberg, Germany
| | - G V Brown
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | | | - S Bernitt
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt, Germany
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
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Buising KL, Thursky KA, Bak N, Skull S, Street A, Presneill JJ, Cades JF, Brown GV. Antibiotic Prescribing in Response to Bacterial Isolates in the Intensive Care Unit. Anaesth Intensive Care 2019; 33:571-7. [PMID: 16235473 DOI: 10.1177/0310057x0503300504] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study aimed to identify potential knowledge-performance gaps in antibiotic prescribing for bacterial isolates in the Intensive Care Unit (ICU) in order to guide the development of interventions such as antibiotic policies, decision support, and improved systems for communication between the laboratory and the bedside. A prospective observational cohort study of all patients admitted to a mixed medical/surgical ICU was undertaken over a six-month period in an Australian adult tertiary hospital. From a cohort of 524 patients, 108 had 303 isolates that were eligible for inclusion. Overall, 14.3% and 30.8% of sterile and non-sterile isolates respectively were associated with inadequate initial antibiotic therapy after identification of the bacteria. After sensitivity results were available inadequate directed therapy was observed in 4.0% and 21.3% of sterile and non-sterile isolates respectively. Problems were most commonly associated with isolates of Pseudomonas spp., Stenotrophomonas spp., Acinetobacter spp., S. aureus, enterococci and group III Enterobacteriaceae. Inadequate antibiotic therapy was found to be independently associated with prolonged length of ICU stay. Narrower spectrum antibiotic therapy was potentially available for 30% of isolates after sensitivity results were known. We conclude that there is scope to improve antibiotic prescribing in the ICU by providing clinicians with access to information regarding local susceptibility patterns and intrinsic resistance of bacteria, and spectra of antibiotic cover. Timely notification of laboratory results at the point of care may also facilitate improved prescribing performance.
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Affiliation(s)
- K L Buising
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Melbourne, Parkville, Victoria
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8
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Lockard TE, Magee EW, Layne DA, Leutenegger MA, Eckart ME, Hell N, Brown GV, Beiersdorfer P. The Warm Electron Beam Ion Trap (WEBIT): An instrument for ground calibration of space-borne x-ray spectrometers. Rev Sci Instrum 2018; 89:10F124. [PMID: 30399834 DOI: 10.1063/1.5039338] [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: 05/07/2018] [Accepted: 08/25/2018] [Indexed: 06/08/2023]
Abstract
The warm electron beam ion trap (WEBIT) at Lawrence Livermore National Laboratory is being developed as a pre-launch, ground calibration source for space-borne, high-throughput, high-resolution x-ray spectrometers, such as the x-ray imaging and spectroscopy mission Resolve quantum calorimeter. Historically, calibration sources for calorimeter spectrometers have relied on characteristic line emission from x-ray tubes, fluorescing metals, and radioactive sources. The WEBIT, by contrast, relies on emission from x-ray transitions in highly charged ions, for example, hydrogen-like and helium-like ions, whose energies are well known and whose line shapes are relatively simple. The WEBIT can create astrophysically relevant ions whose x-ray emission falls in the 0.3-12 keV science bandpass of Resolve and has a portable design advantageous for a calibration source. The WEBIT will be used to help calibrate Resolve's instrumental line shape and gain scale as a function of various operational parameters during both detector subsystem level testing and instrumental level testing.
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Affiliation(s)
- T E Lockard
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E W Magee
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D A Layne
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M A Leutenegger
- NASA-Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - M E Eckart
- NASA-Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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9
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Hell N, Lockard T, Beiersdorfer P, Magee EW, Brown GV, Shepherd R, Arthanayaka T. Experimental comparison of spherically bent HAPG and Ge crystals. Rev Sci Instrum 2018; 89:10F121. [PMID: 30399853 DOI: 10.1063/1.5038003] [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: 04/30/2018] [Accepted: 06/28/2018] [Indexed: 06/08/2023]
Abstract
The Orion high-resolution X-ray (OHREX) imaging spherically bent crystal spectrometer, operated with both image plates and CCD cameras, provides time-averaged plasma diagnostics through high-resolution spectroscopy with good signal-to-noise at the Orion laser facility. In order to provide time-resolved spectra, the OHREX will be outfitted with a streak camera, and in this case, even higher signal to noise will be desired. Using the OHREX's sister instrument, the EBIT High-resolution X-ray (EBHiX) spectrometer, at the LLNL electron beam ion trap EBIT-I, we therefore compare the efficiency of a high-quality Ge (111) crystal (2d = 6.532 Å) with that of a higher integrated reflectivity, but lower-resolution highly annealed pyrolytic graphite (HAPG) crystal (2d = 6.708 Å) in the energy range 2408-2452 eV. We find that the HAPG provides overall more signal across the entire image; however, because of the much better focusing properties of the Ge crystal, the latter provides more signal within the central 100 μm of the spatial profile in the cross-dispersion direction and is thus more suitable for the narrow entrance window of the Livermore-built streak camera.
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Affiliation(s)
- N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T Lockard
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - 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
| | - R Shepherd
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T Arthanayaka
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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10
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Arthanayaka TP, Beiersdorfer P, Brown GV, Hahn M, Hell N, Lockard TE, Savin DW. Measurements of the effective electron density in an electron beam ion trap using extreme ultraviolet spectra and optical imaging. Rev Sci Instrum 2018; 89:10E119. [PMID: 30399824 DOI: 10.1063/1.5036758] [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] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/08/2018] [Indexed: 06/08/2023]
Abstract
In an electron beam ion trap (EBIT), the ions are not confined to the electron beam, but rather oscillate in and out of the beam. As a result, the ions do not continuously experience the full density of the electron beam. To determine the effective electron density, n e,eff, experienced by the ions, the electron beam size, the nominal electron density n e, and the ion distribution around the beam, i.e., the so-called ion cloud, must be measured. We use imaging techniques in the extreme ultraviolet (EUV) and optical to determine these. The electron beam width is measured using 3d → 3p emission from Fe xii and xiii between 185 and 205 Å. These transitions are fast and the EUV emission occurs only within the electron beam. The measured spatial emission profile and variable electron current yield a nominal electron density range of n e ∼ 1011-1013 cm-3. We determine the size of the ion cloud using optical emission from metastable levels of ions with radiative lifetimes longer than the ion orbital periods. The resulting emission maps out the spatial distribution of the ion cloud. We find a typical electron beam radius of ∼60 μm and an ion cloud radius of ∼300 μm. These yield a spatially averaged effective electron density, n e,eff, experienced by the ions in EBIT spanning ∼ 5 × 109-5 × 1011 cm-3.
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Affiliation(s)
- T P Arthanayaka
- Columbia Astrophysics Laboratory, New York, New York 10027, USA
| | - P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Hahn
- Columbia Astrophysics Laboratory, New York, New York 10027, USA
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - T E Lockard
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D W Savin
- Columbia Astrophysics Laboratory, New York, New York 10027, USA
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11
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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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12
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Eckart ME, Boyce KR, Brown GV, Chiao MP, Fujimoto R, Haas D, den Herder JW, Ishisaki Y, Kelley RL, Kilbourne CA, Leutenegger MA, McCammon D, Mitsuda K, Porter FS, Sawada M, Sneiderman GA, Szymkowiak AE, Takei Y, Tashiro M, Tsujimoto M, de Vries CP, Watanabe T, Yamada S, Yamasaki NY. Calibration of the microcalorimeter spectrometer on-board the Hitomi (Astro-H) observatory (invited). Rev Sci Instrum 2016; 87:11D503. [PMID: 27910640 DOI: 10.1063/1.4961075] [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: 06/06/2023]
Abstract
The Hitomi Soft X-ray Spectrometer (SXS) was a pioneering non-dispersive imaging x-ray spectrometer with 5 eV FWHM energy resolution, consisting of an array of 36 silicon-thermistor microcalorimeters at the focus of a high-throughput soft x-ray telescope. The instrument enabled astrophysical plasma diagnostics in the 0.3-12 keV band. We introduce the SXS calibration strategy and corresponding ground calibration measurements that took place from 2012-2015, including both the characterization of the microcalorimeter array and measurements of the x-ray transmission of optical blocking filters.
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Affiliation(s)
- M E Eckart
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - K R Boyce
- NASA Goddard Space Flight Center, Code 592, Greenbelt, Maryland 20771, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M P Chiao
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - R Fujimoto
- Kanazawa University, Kanazawa, Ishikawa 920-1192, Japan
| | - D Haas
- SRON Netherlands Institute for Space Research, Utrecht, The Netherlands
| | - J-W den Herder
- SRON Netherlands Institute for Space Research, Utrecht, The Netherlands
| | - Y Ishisaki
- Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - R L Kelley
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - C A Kilbourne
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - M A Leutenegger
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - D McCammon
- University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - K Mitsuda
- Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagawa 252-5210, Japan
| | - F S Porter
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - M Sawada
- Aoyama Gakuin University, Sagamihara, Kanagawa 252-5258, Japan
| | - G A Sneiderman
- NASA Goddard Space Flight Center, Code 592, Greenbelt, Maryland 20771, USA
| | | | - Y Takei
- Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagawa 252-5210, Japan
| | - M Tashiro
- Saitama University, Sakura-ku, Saitama 338-8570, Japan
| | - M Tsujimoto
- Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagawa 252-5210, Japan
| | - C P de Vries
- SRON Netherlands Institute for Space Research, Utrecht, The Netherlands
| | - T Watanabe
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - S Yamada
- Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - N Y Yamasaki
- Institute of Space and Astronautical Science, JAXA, Sagamihara, Kanagawa 252-5210, Japan
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Beiersdorfer P, Magee EW, Hell N, Brown GV. Imaging crystal spectrometer for high-resolution x-ray measurements on electron beam ion traps and tokamaks. Rev Sci Instrum 2016; 87:11E339. [PMID: 27910570 DOI: 10.1063/1.4962049] [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: 06/06/2023]
Abstract
We describe a crystal spectrometer implemented on the Livermore electron beam ion traps that employ two spherically bent quartz crystals and a cryogenically cooled back-illuminated charge-coupled device detector to measure x rays with a nominal resolving power of λ/Δλ ≥ 10 000. Its focusing properties allow us to record x rays either with the plane of dispersion perpendicular or parallel to the electron beam and, thus, to preferentially select one of the two linear x-ray polarization components. Moreover, by choice of dispersion plane and focussing conditions, we use the instrument either to image the distribution of the ions within the 2 cm long trap region, or to concentrate x rays of a given energy to a point on the detector, which optimizes the signal-to-noise ratio. We demonstrate the operation and utility of the new instrument by presenting spectra of Mo34+, which prepares the instrument for use as a core impurity diagnostic on the NSTX-U spherical torus and other magnetic fusion devices that employ molybdenum as plasma facing components.
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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
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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14
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Brown GV, Beiersdorfer P, Hell N, Magee E. Experimentally determining the relative efficiency of spherically bent germanium and quartz crystals. Rev Sci Instrum 2016; 87:11D620. [PMID: 27910582 DOI: 10.1063/1.4962037] [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: 06/06/2023]
Abstract
We have used the EBIT-I electron beam ion trap at the Lawrence Livermore National Laboratory and a duplicate Orion High Resolution X-ray Spectrometer (OHREX) to measure the relative efficiency of a spherically bent quartz (101̄1) crystal (2d = 6.687 Å) and a spherically bent germanium (111) crystal (2d = 6.532 Å). L-shell X-ray photons from highly charged molybdenum ions generated in EBIT-I were simultaneously focussed and Bragg reflected by each crystal, both housed in a single spectrometer, onto a single CCD X-ray detector. The flux from each crystal was then directly compared. Our results show that the germanium crystal has a reflection efficiency significantly better than the quartz crystal, however, the energy resolution is significantly worse. Moreover, we find that the spatial focussing properties of the germanium crystal are worse than those of the quartz crystal. Details of the experiment are presented, and we discuss the advantages of using either crystal on a streak-camera equipped OHREX spectrometer.
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Affiliation(s)
- G V Brown
- Physics Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - P Beiersdorfer
- Physics Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - N Hell
- Physics Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - E Magee
- Physics Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
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15
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Leutenegger MA, Beiersdorfer P, Betancourt-Martinez GL, Brown GV, Hell N, Kelley RL, Kilbourne CA, Magee EW, Porter FS. Characterization of an atomic hydrogen source for charge exchange experiments. Rev Sci Instrum 2016; 87:11E516. [PMID: 27910505 DOI: 10.1063/1.4959919] [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 characterized the dissociation fraction of a thermal dissociation atomic hydrogen source by injecting the mixed atomic and molecular output of the source into an electron beam ion trap containing highly charged ions and recording the x-ray spectrum generated by charge exchange using a high-resolution x-ray calorimeter spectrometer. We exploit the fact that the charge exchange state-selective capture cross sections are very different for atomic and molecular hydrogen incident on the same ions, enabling a clear spectroscopic diagnostic of the neutral species.
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Affiliation(s)
- M A Leutenegger
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - P Beiersdorfer
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA
| | | | - G V Brown
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA
| | - N Hell
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA
| | - R L Kelley
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - C A Kilbourne
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
| | - E W Magee
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA
| | - F S Porter
- NASA Goddard Space Flight Center, Code 662, Greenbelt, Maryland 20771, USA
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16
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Petkov EE, Safronova AS, Kantsyrev VL, Shlyaptseva VV, Rawat RS, Tan KS, Beiersdorfer P, Hell N, Brown GV. L-shell spectroscopic diagnostics of radiation from krypton HED plasma sources. Rev Sci Instrum 2016; 87:11E315. [PMID: 27910569 DOI: 10.1063/1.4960534] [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: 06/06/2023]
Abstract
X-ray spectroscopy is a useful tool for diagnosing plasma sources due to its non-invasive nature. One such source is the dense plasma focus (DPF). Recent interest has developed to demonstrate its potential application as a soft x-ray source. We present the first spectroscopic studies of krypton high energy density plasmas produced on a 3 kJ DPF device in Singapore. In order to diagnose spectral features, and to obtain a more comprehensive understanding of plasma parameters, a new non-local thermodynamic equilibrium L-shell kinetic model for krypton was developed. It has the capability of incorporating hot electrons, with different electron distribution functions, in order to examine the effects that they have on emission spectra. To further substantiate the validity of this model, it is also benchmarked with data gathered from experiments on the electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory, where data were collected using the high resolution EBIT calorimeter spectrometer.
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Affiliation(s)
- E E Petkov
- University of Nevada, Reno, Nevada 89557, USA
| | | | | | | | - R S Rawat
- National Institute of Education, Nanyang Technological University, Singapore 637616, Singapore
| | - K S Tan
- National Institute of Education, Nanyang Technological University, Singapore 637616, Singapore
| | - P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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17
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Hell N, Beiersdorfer P, Magee EW, Brown GV. Calibration of the OHREX high-resolution imaging crystal spectrometer at the Livermore electron beam ion traps. Rev Sci Instrum 2016; 87:11D604. [PMID: 27910351 DOI: 10.1063/1.4959947] [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 report the calibration of the Orion High-Resolution X-ray (OHREX) imaging crystal spectrometer at the EBIT-I electron beam ion trap at Livermore. Two such instruments, dubbed OHREX-1 and OHREX-2, are fielded for plasma diagnostics at the Orion laser facility in the United Kingdom. The OHREX spectrometer can simultaneously house two spherically bent crystals with a radius of curvature of r = 67.2 cm. The focusing properties of the spectrometer allow both for larger distance to the source due to the increase in collected light and for observation of extended sources. OHREX is designed to cover a 2.5°-3° spectral range at Bragg angles around 51.3°. The typically high resolving powers at these large Bragg angles are ideally suited for line shape diagnostics. For instance, the nominal resolving power of the instrument (>10 000) is much higher than the effective resolving power associated with the Doppler broadening due to the temperature of the trapped ions in EBIT-I. The effective resolving power is only around 3000 at typical EBIT-I conditions, which nevertheless is sufficient to set up and test the instrument's spectral characteristics. We have calibrated the spectral range for a number of crystals using well known reference lines in the first and second order and derived the ion temperatures from these lines. We have also made use of the 50 μm size of the EBIT-I source width to characterize the spatial focusing of the spectrometer.
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Affiliation(s)
- N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - 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
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18
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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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19
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Marrs RE, Widmann K, Brown GV, Heeter RF, MacLaren SA, May MJ, Moore AS, Schneider MB. Use of a priori spectral information in the measurement of x-ray flux with filtered diode arrays. Rev Sci Instrum 2015; 86:103511. [PMID: 26520959 DOI: 10.1063/1.4934542] [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: 06/05/2023]
Abstract
Filtered x-ray diode (XRD) arrays are often used to measure x-ray spectra vs. time from spectrally continuous x-ray sources such as hohlraums. A priori models of the incident x-ray spectrum enable a more accurate unfolding of the x-ray flux as compared to the standard technique of modifying a thermal Planckian with spectral peaks or dips at the response energy of each filtered XRD channel. A model x-ray spectrum consisting of a thermal Planckian, a Gaussian at higher energy, and (in some cases) a high energy background provides an excellent fit to XRD-array measurements of x-ray emission from laser heated hohlraums. If high-resolution measurements of part of the x-ray emission spectrum are available, that information can be included in the a priori model. In cases where the x-ray emission spectrum is not Planckian, candidate x-ray spectra can be allowed or excluded by fitting them to measured XRD voltages. Examples are presented from the filtered XRD arrays, named Dante, at the National Ignition Facility and the Laboratory for Laser Energetics.
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Affiliation(s)
- R E Marrs
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - K Widmann
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - S A MacLaren
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - M J May
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
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21
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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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22
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Magee EW, Beiersdorfer P, Brown GV, Hell N. Rare-earth neutral metal injection into an electron beam ion trap plasma. Rev Sci Instrum 2014; 85:11E820. [PMID: 25430385 DOI: 10.1063/1.4892899] [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 designed and implemented a neutral metal vapor injector on the SuperEBIT high-energy electron beam ion trap at the Lawrence Livermore National Laboratory. A horizontally directed vapor of a europium metal is created using a thermal evaporation technique. The metal vapor is then spatially collimated prior to injection into the trap. The source's form and quantity constraints are significantly reduced making plasmas out of metal with vapor pressures ≤10(-7) Torr at ≥1000 °C more obtainable. A long pulsed or constant feed metal vapor injection method adds new flexibility by varying the timing of injection and rate of material being introduced into the trap.
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Affiliation(s)
- E W Magee
- 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
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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23
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Beiersdorfer P, Magee EW, Brown GV, Hell N, Träbert E, Widmann K. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trap. Rev Sci Instrum 2014; 85:11E422. [PMID: 25430329 DOI: 10.1063/1.4891875] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [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
A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Å to above 300 Å. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 μm wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Å above 100 Å, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.
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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
| | - N Hell
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E Träbert
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - K Widmann
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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24
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May MJ, Brown GV, Halvorson C, Schmidt A, Bower D, Tran B, Lewis P, Hagen C. Gamma ray measurements with photoconductive detectors using a dense plasma focus. Rev Sci Instrum 2014; 85:11E117. [PMID: 25430296 DOI: 10.1063/1.4891876] [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
Photons in the MeV range emitted from the dense plasma focus (DPF) at the NSTec North Las Vegas Facility have been measured with both neutron-damaged GaAs and natural diamond photoconductive detectors (PCDs). The DPF creates or "pinches" plasmas of various gases (e.g., H2, D2, Ne, Ar., etc.) that have enough energy to create MeV photons from either bremsstrahlung and/or (n,n(')) reactions if D2 gas is used. The high bandwidth of the PCDs enabled the first ever measurement of the fast micro-pinches present in DPF plasmas. Comparisons between a slower more conventional scintillator/photomultiplier tube based nuclear physics detectors were made to validate the response of the PCDs to fast intense MeV photon signals. Significant discrepancies in the diamond PCD responses were evident.
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Affiliation(s)
- M J May
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - G V Brown
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - C Halvorson
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - A Schmidt
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - D Bower
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - B Tran
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - P Lewis
- L-281 Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94551, USA
| | - C Hagen
- National Security Technologies, LLC, P.O. Box 98518, Las Vegas, Nevada 89193-8518, USA
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25
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Marrs RE, Brown GV, Emig JA, Heeter RF. System for calibrating the energy-dependent response of an elliptical Bragg-crystal spectrometer. Rev Sci Instrum 2014; 85:11D626. [PMID: 25430202 DOI: 10.1063/1.4892552] [Citation(s) in RCA: 3] [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] [Indexed: 06/04/2023]
Abstract
A multipurpose spectrometer (MSPEC) with elliptical crystals is in routine use to obtain x-ray spectra from laser produced plasmas in the energy range 1.0-9.0 keV. Knowledge of the energy-dependent response of the spectrometer is required for an accurate comparison of the intensities of x-ray lines of different energy. The energy-dependent response of the MSPEC has now been derived from the spectrometer geometry and calibration information on the response of its components, including two different types of detectors. Measurements of the spectrometer response with a laboratory x-ray source are used to test the calculated response and provide information on crystal reflectivity and uniformity.
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Affiliation(s)
- R E Marrs
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - J A Emig
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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26
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Beiersdorfer P, Träbert E, Brown GV, Clementson J, Thorn DB, Chen MH, Cheng KT, Sapirstein J. Hyperfine splitting of the 2s1/2 and 2p1/2 levels in Li- and be-like ions of (59)(141) Pr. Phys Rev Lett 2014; 112:233003. [PMID: 24972204 DOI: 10.1103/physrevlett.112.233003] [Citation(s) in RCA: 3] [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: 04/14/2014] [Indexed: 06/03/2023]
Abstract
High-resolution spectroscopy of the 2s(1/2)-2p(1/2) transition in the extreme ultraviolet region is shown to resolve the level splitting induced by the nuclear magnetic field of both the 2s(1/2) and the 2p(1/2) levels in lithiumlike (141)Pr(56+) and of the 2s(1/2)2p(1/2) (3)P(1) level in berylliumlike (141)Pr(55+). The (141)Pr ions are an ideal test of this measurement approach because their energy levels are known well from first principles and are unaffected by small energy contributions from QED and nuclear magnetization effects. The accuracy attained in the measured 196.5 ± 1.2 meV 2s(1/2) splitting is more than an order of magnitude better than that achieved before using crystal spectroscopy of the 2s(1/2)-2p(3/2) x-ray transition and at the level needed to implement a proposed scheme for disentangling the contributions from QED and nuclear magnetization effects in higher-Z ions, such as (209)Bi.
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Affiliation(s)
- P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - E Träbert
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - J Clementson
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - D B Thorn
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - M H Chen
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - K T Cheng
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
| | - J Sapirstein
- University of Notre Dame, Notre Dame, Indiana 46556, USA
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27
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Rudolph JK, Bernitt S, Epp SW, Steinbrügge R, Beilmann C, Brown GV, Eberle S, Graf A, Harman Z, Hell N, Leutenegger M, Müller A, Schlage K, Wille HC, Yavaş H, Ullrich J, Crespo López-Urrutia JR. X-ray resonant photoexcitation: linewidths and energies of Kα transitions in highly charged Fe ions. Phys Rev Lett 2013; 111:103002. [PMID: 25166661 DOI: 10.1103/physrevlett.111.103002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Indexed: 06/03/2023]
Abstract
Photoabsorption by and fluorescence of the Kα transitions in highly charged iron ions are essential mechanisms for x-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main Kα transitions in highly charged iron ions from heliumlike to fluorinelike (Fe24+ to Fe17+) using monochromatic x rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in x-ray binary stars and active galactic nuclei.
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Affiliation(s)
- J K Rudolph
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany and Institut für Atom- und Molekülphysik, Justus-Liebig-Universität Gießen, Leihgesterner Weg 217, 35392 Gießen, Germany
| | - S Bernitt
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - S W Epp
- Max Planck Advanced Study Group, CFEL, Notkestraße 85, 22607 Hamburg, Germany
| | - R Steinbrügge
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - C Beilmann
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany and Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany
| | - G V Brown
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - S Eberle
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - A Graf
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
| | - Z Harman
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany and ExtreMe Matter Institute (EMMI), Planckstraße 1, 64291 Darmstadt, Germany
| | - N Hell
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA and Dr. Karl Remeis-Observatory and ECAP, Universität Erlangen Nürnberg, Sternwartstraße 7, 96049 Bamberg, Germany
| | - M Leutenegger
- NASA/Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771, USA and Center for Space Sciences and Technology, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA
| | - A Müller
- Institut für Atom- und Molekülphysik, Justus-Liebig-Universität Gießen, Leihgesterner Weg 217, 35392 Gießen, Germany
| | - K Schlage
- Deutsches Elektronen-Synchrotron (PETRA III), Notkestraße 85, 22607 Hamburg, Germany
| | - H-C Wille
- Deutsches Elektronen-Synchrotron (PETRA III), Notkestraße 85, 22607 Hamburg, Germany
| | - H Yavaş
- Deutsches Elektronen-Synchrotron (PETRA III), Notkestraße 85, 22607 Hamburg, Germany
| | - J Ullrich
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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28
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Beiersdorfer P, Brown GV, Graf AT, Bitter M, Hill KW, Kelley RL, Kilbourne CA, Leutenegger MA, Porter FS. Rest-wavelength fiducials for the ITER core imaging x-ray spectrometer. Rev Sci Instrum 2012; 83:10E111. [PMID: 23126933 DOI: 10.1063/1.4733318] [Citation(s) in RCA: 2] [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] [Indexed: 06/01/2023]
Abstract
Absolute wavelength references are needed to derive the plasma velocities from the Doppler shift of a given line emitted by a moving plasma. We show that such reference standards exist for the strongest x-ray line in neonlike W(64+), which has become the line of choice for the ITER (Latin "the way") core imaging x-ray spectrometer. Close-by standards are the Hf Lβ(3) line and the Ir Lα(2) line, which bracket the W(64+) line by ±30 eV; other standards are given by the Ir Lα(1) and Lα(2) lines and the Hf Lβ(1) and Lβ(2) lines, which bracket the W(64+) line by ±40 and ±160 eV, respectively. The reference standards can be produced by an x-ray tube built into the ITER spectrometer. We present spectra of the reference lines obtained with an x-ray microcalorimeter and compare them to spectra of the W(64+) line obtained both with an x-ray microcalorimeter and a crystal spectrometer.
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Affiliation(s)
- P Beiersdorfer
- Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
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29
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Denholm JT, Leslie DE, Jenkin GA, Darby J, Johnson PDR, Graham SM, Brown GV, Sievers A, Globan M, Brown LK, McBryde ES. Long-term follow-up of contacts exposed to multidrug-resistant tuberculosis in Victoria, Australia, 1995-2010. Int J Tuberc Lung Dis 2012; 16:1320-5. [PMID: 22863690 DOI: 10.5588/ijtld.12.0092] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING The effectiveness of public health strategies following exposure to multidrug-resistant tuberculosis (MDR-TB) is not clear. OBJECTIVE To perform long-term follow-up of MDR-TB contacts and review individual outcomes and management approaches. DESIGN Retrospective review of MDR-TB contacts identified by the Victorian Department of Health from 1995 to 2010. Health records, including personal medical and pharmacy records and statewide clinical and laboratory TB databases, were searched to identify management strategies and individual outcomes. RESULTS A total of 570 contacts of 47 MDR-TB cases were identified, with a total follow-up period of 3093 person-years of observation (PYO) since exposure. Of 570 contacts, 49 (8.6%) were considered likely to have been infected with Mycobacterium tuberculosis from index cases, and 11/49 (22.5%) of these were prescribed preventive therapy tailored to isolate susceptibility. No MDR-TB cases occurred in those receiving preventive treatment, while two cases were observed in those not treated (incidence 2878/100 000 PYO during the first 2 years post exposure). CONCLUSIONS The risk of MDR-TB transmission to close contacts in this low-prevalence setting highlights the potential for public health strategies involving preventive treatment.
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Affiliation(s)
- J T Denholm
- Victorian Infectious Diseases Service, Royal Melbourne Hospital and Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.
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Magee EW, Dunn J, Brown GV, Cone KV, Park J, Porter FS, Kilbourne CA, Kelley RL, Beiersdorfer P. Calibration of a high resolution grating soft x-ray spectrometer. Rev Sci Instrum 2010; 81:10E314. [PMID: 21034013 DOI: 10.1063/1.3494276] [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: 05/30/2023]
Abstract
The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10-50 Å waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources.
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Affiliation(s)
- E W Magee
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
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31
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Cone KV, Dunn J, Schneider MB, Baldis HA, Brown GV, Emig J, James DL, May MJ, Park J, Shepherd R, Widmann K. Development of a time-resolved soft x-ray spectrometer for laser produced plasma experiments. Rev Sci Instrum 2010; 81:10E318. [PMID: 21034016 DOI: 10.1063/1.3492407] [Citation(s) in RCA: 2] [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: 05/30/2023]
Abstract
A 2400 lines/mm variable-spaced grating spectrometer has been used to measure soft x-ray emission (8-22 Å) from laser-produced plasma experiments at Lawrence Livermore National Laboratory's Compact Multipulse Terrawatt (COMET) Laser Facility. The spectrometer was coupled to a Kentech x-ray streak camera to study the temporal evolution of soft x rays emitted from the back of the Mylar and the copper foils irradiated at 10(15) W/cm(2). The instrument demonstrated a resolving power of ∼120 at 19 Å with a time resolution of 31 ps. The time-resolved copper emission spectrum was consistent with a photodiode monitoring the laser temporal pulse shape and indicated that the soft x-ray emission follows the laser heating of the target. The time and spectral resolutions of this diagnostic make it useful for studies of high temperature plasmas.
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Affiliation(s)
- K V Cone
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
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Beiersdorfer P, Brown GV, Clementson J, Dunn J, Morris K, Wang E, Kelley RL, Kilbourne CA, Porter FS, Bitter M, Feder R, Hill KW, Johnson D, Barnsley R. The ITER core imaging x-ray spectrometer: x-ray calorimeter performance. Rev Sci Instrum 2010; 81:10E323. [PMID: 21034021 DOI: 10.1063/1.3495789] [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: 05/30/2023]
Abstract
We describe the anticipated performance of an x-ray microcalorimeter instrument on ITER. As part of the core imaging x-ray spectrometer, the instrument will augment the imaging crystal spectrometers by providing a survey of the concentration of heavy ion plasma impurities in the core and possibly ion temperature values from the emission lines of different elemental ions located at various radial positions.
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Affiliation(s)
- P Beiersdorfer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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33
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Park J, Brown GV, Schneider MB, Baldis HA, Beiersdorfer P, Cone KV, Kelley RL, Kilbourne CA, Magee EW, May MJ, Porter FS. Calibration of a flat field soft x-ray grating spectrometer for laser produced plasmas. Rev Sci Instrum 2010; 81:10E319. [PMID: 21034017 DOI: 10.1063/1.3495790] [Citation(s) in RCA: 2] [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: 05/30/2023]
Abstract
We have calibrated the x-ray response of a variable line spaced grating spectrometer, known as the VSG, at the Fusion and Astrophysics Data and Diagnostic Calibration Facility at the Lawrence Livermore National Laboratory (LLNL). The VSG has been developed to diagnose laser produced plasmas, such as those created at the Jupiter Laser Facility and the National Ignition Facility at LLNL and at both the Omega and Omega EP lasers at the University of Rochester's Laboratory for Laser Energetics. The bandwidth of the VSG spans the range of ∼6-60 Å. The calibration results presented here include the VSG's dispersion and quantum efficiency. The dispersion is determined by measuring the x rays emitted from the hydrogenlike and heliumlike ions of carbon, nitrogen, oxygen, neon, and aluminum. The quantum efficiency is calibrated to an accuracy of 30% or better by normalizing the x-ray intensities recorded by the VSG to those simultaneously recorded by an x-ray microcalorimeter spectrometer.
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Affiliation(s)
- J Park
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808, USA.
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34
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Leutenegger MA, Beiersdorfer P, Brown GV, Kelley RL, Kilbourne CA, Porter FS. Measurement of anomalously strong emission from the 1s-9p transition in the spectrum of H-like phosphorus following charge exchange with molecular hydrogen. Phys Rev Lett 2010; 105:063201. [PMID: 20867978 DOI: 10.1103/physrevlett.105.063201] [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: 01/19/2010] [Revised: 06/10/2010] [Indexed: 05/29/2023]
Abstract
We have measured K-shell x-ray spectra of highly ionized argon and phosphorus following charge exchange with molecular hydrogen at low collision energy in an electron beam ion trap using an x-ray calorimeter array with ∼6 eV resolution. We find that the emission at the high end of the Lyman series is greater by a factor of 2 for phosphorus than for argon, even though the measurement was performed concurrently and the atomic numbers are similar. This does not agree with current theoretical models and deviates from the trend observed in previous measurements.
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Affiliation(s)
- M A Leutenegger
- NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
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35
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Pinder M, Moorthy VS, Akanmori BD, Genton B, Brown GV. MALVAC 2009: progress and challenges in development of whole organism malaria vaccines for endemic countries, 3-4 June 2009, Dakar, Senegal. Vaccine 2010; 28:4695-702. [PMID: 20470799 DOI: 10.1016/j.vaccine.2010.04.091] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 04/20/2010] [Accepted: 04/27/2010] [Indexed: 10/19/2022]
Abstract
Research and development into whole organism malaria vaccines is progressing rapidly thanks to the major investments over recent years from several funders, and the commitment and interest of many leading researchers. Progress includes the discovery of potential new candidate vaccines and the start of the first phase 1/2a clinical trial of the radiation attenuated sporozoite approach for Plasmodium falciparum, under US Food and Drug Administration regulatory oversight. A group of leading scientists, clinical trialists and stakeholders, together with representatives of regulatory authorities including some from African countries, met recently to document the issues that will require detailed consideration to assess this promising approach. Questions related to scale-up, quality, purity and consistency of a manufacturing process using mosquitoes to generate a commercial product, and demonstration of the stability of attenuated sporozoites will need further work. Should a high level of efficacy be demonstrated in clinical challenge studies, it will become a priority to agree in which populations and age groups questions about strain-transcendence and duration of efficacy should be answered, and how clinical development can progress with an approach based on cryopreservation in liquid nitrogen.
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Affiliation(s)
- M Pinder
- MRC Laboratories, PO Box 273, Fajara, The Gambia
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36
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Porter FS, Beiersdorfer P, Brown GV, Gu MF, Kelley RL, Kahn S, Kilbourne CA, Thorn DB. Evolution of X-ray calorimeter spectrometers at the Lawrence Livermore Electron Beam Ion Trap. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/163/1/012105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [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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37
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Brown GV, Beiersdorfer P, Emig J, Frankel M, Gu MF, Heeter RF, Magee E, Thorn DB, Widmann K, Kelley RL, Kilbourne CA, Porter FS. Rapid, absolute calibration of x-ray filters employed by laser-produced plasma diagnostics. Rev Sci Instrum 2008; 79:10E309. [PMID: 19044471 DOI: 10.1063/1.2965214] [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: 05/27/2023]
Abstract
The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are detected using the high resolution EBIT Calorimeter Spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the x-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated x-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed.
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Affiliation(s)
- G V Brown
- Department of Physical Sciences, High Energy Density Physics and Astrophysics Division, Lawrence Livermore National Laboratory, 7000 East Avenue, L-260, Livermore, California 94550, USA
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Dunn J, Magee EW, Shepherd R, Chen H, Hansen SB, Moon SJ, Brown GV, Gu MF, Beiersdorfer P, Purvis MA. High resolution soft x-ray spectroscopy of low Z K-shell emission from laser-produced plasmas. Rev Sci Instrum 2008; 79:10E314. [PMID: 19044476 DOI: 10.1063/1.2968704] [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: 05/27/2023]
Abstract
A large radius, R=44.3 m, high resolution grating spectrometer (HRGS) with 2400 lines/mm variable line spacing has been designed for laser-produced plasma experiments conducted at the Lawrence Livermore National Laboratory Jupiter Laser Facility. The instrument has been run with a low-noise, charge-coupled device detector to record high signal-to-noise spectra in the 10-50 A wavelength range. The instrument can be run with a 10-20 microm wide slit to achieve the best spectral resolving power, approaching 1000 and similar to crystal spectrometers at 12-20 A, or in slitless operation with a small symmetrical emission source. We describe preliminary spectra emitted from various H-like and He-like low Z ion plasmas heated by 100-500 ps (full width at half maximum), 527 nm wavelength laser pulses. This instrument can be developed as a useful spectroscopy platform relevant to laboratory-based astrophysics as well as high energy density plasma studies.
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Affiliation(s)
- J Dunn
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA.
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Heeter RF, Anderson SG, Booth R, Brown GV, Emig J, Fulkerson S, McCarville T, Norman D, Schneider MB, Young BKF. OZSPEC-2: an improved broadband high-resolution elliptical crystal x-ray spectrometer for high-energy density physics experiments (invited). Rev Sci Instrum 2008; 79:10E303. [PMID: 19044465 DOI: 10.1063/1.2981180] [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: 05/27/2023]
Abstract
A novel time, space, and energy-resolved x-ray spectrometer has been developed which produces, in a single snapshot, a broadband and relatively calibrated spectrum of the x-ray emission from a high-energy density laboratory plasma. The opacity zipper spectrometer (OZSPEC-1) records a nearly continuous spectrum for x-ray energies from 240 to 5800 eV in a single shot. The second-generation OZSPEC-2, detailed in this work, records fully continuous spectra on a single shot from any two of these three bands: 270-650, 660-1580, and 1960-4720 eV. These instruments thus record thermal and line radiation from a wide range of plasmas. These instruments' single-shot bandwidth is unmatched in a time-gated spectrometer; conversely, other broadband instruments are either time-integrated (using crystals or gratings), lack spectral resolution (diode arrays), or cover a lower energy band (gratings). The OZSPECs are based on the zipper detector, a large-format (100x35 mm) gated microchannel plate detector, with spectra dispersed along the 100 mm dimension. OZSPEC-1 and -2 both use elliptically bent crystals of OHM, RAP, and/or PET. Individual spectra are gated in 100 ps. OZSPEC-2 provides one-dimensional spatial imaging with 30-50 microm resolution over a 1500 microm field of view at the source. The elliptical crystal design yields broad spectral coverage with resolution E/DeltaE>500, strong rejection of hard x-ray backgrounds, and negligible source broadening for extended sources. Near-term applications include plasma opacity measurements, detailed spectra of inertial fusion Hohlraums, and laboratory astrophysics experiments.
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Affiliation(s)
- R F Heeter
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA.
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Träbert E, Hansen SB, Beiersdorfer P, Brown GV, Widmann K, Chung HK. L-shell spectroscopy of Au as a temperature diagnostic tool. Rev Sci Instrum 2008; 79:10E313. [PMID: 19044475 DOI: 10.1063/1.2953443] [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: 05/27/2023]
Abstract
In order to develop plasma diagnostic for reduced-size hot Hohlraums under laser irradiation, we have studied the L-shell emission from highly charged gold ions in the SuperEBIT electron beam ion trap. The resolving power necessary to identify emission features from individual charge states in a picket-fence pattern has been estimated, and the observed radiation features have been compared with atomic structure calculations. We find that the strong 3d(5/2)-->2p(3/2) emission features are particularly useful in determining the charge state distribution and average ion charge Z, which are strongly sensitive to the electron temperature.
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Affiliation(s)
- E Träbert
- High Temperature and Astrophysics Division, Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA.
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Buising KL, Thursky KA, Robertson MB, Black JF, Street AC, Richards MJ, Brown GV. Electronic antibiotic stewardship--reduced consumption of broad-spectrum antibiotics using a computerized antimicrobial approval system in a hospital setting. J Antimicrob Chemother 2008; 62:608-16. [PMID: 18550680 DOI: 10.1093/jac/dkn218] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVES Antibiotic stewardship is important, but the ideal strategy for providing stewardship in a hospital setting is unknown. A practical, sustainable and transferable strategy is needed. This study evaluates the impact of a novel computerized antimicrobial approval system on antibiotic-prescribing behaviour in a hospital. Effects on drug consumption, antibiotic resistance patterns of local bacteria and patient outcomes were monitored. METHODS The study was conducted at a tertiary referral teaching hospital in Melbourne, Australia. The system was deployed in January 2005 and guided the use of 28 restricted antimicrobials. Data were collected over 7 years: 5 years before and 2 years after deployment. Uptake of the system was evaluated using an in-built audit trail. Drug utilization was prospectively monitored using pharmacy data (as defined daily doses per 1000 bed-days) and analysed via time-series analysis with segmental linear regression. Antibiograms of local bacteria were prospectively evaluated. In-hospital mortality and length of stay for patients with Gram-negative bacteraemia were also reported. RESULTS Between 250 and 300 approvals were registered per month during 2006. The gradients in the use of third- and fourth-generation cephalosporins (+0.52, -0.05, -0.39; P < 0.01), glycopeptides (+0.27, -0.53; P = 0.09), carbapenems (+0.12, -0.24; P = 0.21), aminoglycosides (+0.15, -0.27; P < 0.01) and quinolones (+0.76, +0.11; P = 0.08) all fell after deployment, while extended-spectrum penicillin use increased. Trends in increased susceptibility of Staphylococcus aureus to methicillin and improved susceptibility of Pseudomonas spp. to many antibiotics were observed. No increase in adverse outcomes for patients with Gram-negative bacteraemia was observed. CONCLUSIONS The system was successfully adopted and significant changes in antimicrobial usage were demonstrated.
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Affiliation(s)
- K L Buising
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, Vic. 3050, Australia.
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Brown GV, Hansen SB, Träbert E, Beiersdorfer P, Widmann K, Chen H, Chung HK, Clementson JHT, Gu MF, Thorn DB. Investigation of the 2p_{32}-3d_{52} line emission of Au;{53+}-Au;{69+} for diagnosing high energy density plasmas. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 77:066406. [PMID: 18643382 DOI: 10.1103/physreve.77.066406] [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: 02/05/2008] [Indexed: 05/26/2023]
Abstract
Measurements of the L -shell emission of highly charged gold ions were made under controlled laboratory conditions using the SuperEBIT electron beam ion trap, allowing detailed spectral observations of lines from Fe-like Au53+ through Ne-like Au69+ . Using atomic data from the Flexible Atomic Code, we have identified strong 3d_{52}-->2p_{32} emission features that can be used to diagnose the charge state distribution in high energy density plasmas, such as those found in the laser entrance hole of hot hohlraum radiation sources. We provide collisional-radiative calculations of the average ion charge Z as a function of temperature and density, which can be used to relate charge state distributions inferred from 3d_{52}-->2p_{32} emission features to plasma conditions, and investigate the effects of plasma density on calculated L -shell Au emission spectra.
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Affiliation(s)
- G V Brown
- Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA
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Anders RF, Shi PT, Scanlon DB, Leach SJ, Coppel RL, Brown GV, Stahl HD, Kemp DJ. Antigenic repeat structures in proteins of Plasmodium falciparum. Ciba Found Symp 2007; 119:164-83. [PMID: 2426051 DOI: 10.1002/9780470513286.ch10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The majority of malaria antigens that have been cloned contain short sequence repeats which encode antigenic epitopes that are naturally immunogenic. Synthetic peptides have been used to show that natural antibody responses to a strain-specific Plasmodium falciparum S antigen are largely directed against epitopes encoded in an 11-amino acid sequence that is repeated approximately 100 times in the molecule. A 16-amino acid peptide conjugated to bovine serum albumin induced antibodies specific for the S antigen of the homologous isolate. Synthetic peptides have also been used to confirm the natural immunogenicity of epitopes encoded within two blocks of related repeats in the Ring-infected Erythrocyte Surface Antigen (RESA). A 16-amino acid peptide, comprising four repeats of the tetrameric sequence EENV, induced antibodies reactive with the native molecule. Detailed analyses of these anti-peptide antisera indicate that short sequence repeats express more than one epitope, some of which may cross-react with other repeat structures.
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Buising KL, Thursky KA, Black JF, MacGregor L, Street AC, Kennedy MP, Brown GV. Empiric antibiotic prescribing for patients with community-acquired pneumonia: where can we improve? Intern Med J 2007; 38:174-7. [DOI: 10.1111/j.1445-5994.2007.01455.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Träbert E, Beiersdorfer P, Brown GV. Observation of hyperfine mixing in measurements of a magnetic octupole decay in isotopically pure nickel-like 129Xe and 132Xe ions. Phys Rev Lett 2007; 98:263001. [PMID: 17678086 DOI: 10.1103/physrevlett.98.263001] [Citation(s) in RCA: 2] [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: 12/21/2006] [Indexed: 05/16/2023]
Abstract
We present measurements of high statistical significance of the rate of the magnetic octupole (M3 ) decay in nickel-like ions of isotopically pure 129Xe and 132Xe. On 132Xe, an isotope with zero nuclear spin and therefore without hyperfine structure, the lifetime of the metastable level was established as (15.06+/-0.24) ms. On 129Xe, an additional fast (2.7+/-0.1 ms) decay component was established that represents hyperfine mixing with a level that decays by electric quadrupole (E2 ) radiation.
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Affiliation(s)
- E Träbert
- High Temperature and Astrophysics Division, Lawrence Livermore National Laboratory, Livermore, California 94550-9234, USA.
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Skull SA, Andrews RM, Byrnes GB, Campbell DA, Nolan TM, Brown GV, Kelly HA. ICD-10 codes are a valid tool for identification of pneumonia in hospitalized patients aged > or = 65 years. Epidemiol Infect 2007; 136:232-40. [PMID: 17445319 PMCID: PMC2870806 DOI: 10.1017/s0950268807008564] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
This study examines the validity of using ICD-10 codes to identify hospitalized pneumonia cases. Using a case-cohort design, subjects were randomly selected from monthly cohorts of patients aged > or = 65 years discharged from April 2000 to March 2002 from two large tertiary Australian hospitals. Cases had ICD-10-AM codes J10-J18 (pneumonia); the cohort sample was randomly selected from all discharges, frequency matched to cases by month. Codes were validated against three comparators: medical record notation of pneumonia, chest radiograph (CXR) report and both. Notation of pneumonia was determined for 5098/5101 eligible patients, and CXR reports reviewed for 3349/3464 (97%) patients with a CXR. Coding performed best against notation of pneumonia: kappa 0.95, sensitivity 97.8% (95% CI 97.1-98.3), specificity 96.9% (95% CI 96.2-97.5), positive predictive value (PPV) 96.2% (95% CI 95.4-97.0) and negative predictive value (NPV) 98.2% (95% CI 97.6-98.6). When medical record notation of pneumonia is used as the standard, ICD-10 codes are a valid method for retrospective ascertainment of hospitalized pneumonia cases and appear superior to use of complexes of symptoms and signs, or radiology reports.
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Affiliation(s)
- S A Skull
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia.
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Beck BR, Becker JA, Beiersdorfer P, Brown GV, Moody KJ, Wilhelmy JB, Porter FS, Kilbourne CA, Kelley RL. Energy splitting of the ground-state doublet in the nucleus 229Th. Phys Rev Lett 2007; 98:142501. [PMID: 17501268 DOI: 10.1103/physrevlett.98.142501] [Citation(s) in RCA: 15] [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: 10/24/2006] [Indexed: 05/15/2023]
Abstract
The energy splitting of the 229Th ground-state doublet is measured to be 7.6+/-0.5 eV, significantly greater than earlier measurements. Gamma rays produced following the alpha decay of 233U (105 muCi) were counted in the NASA/electron beam ion trap x-ray microcalorimeter spectrometer with an experimental energy resolution of 26 eV (FWHM). A difference technique was applied to the gamma-ray decay of the 71.82 keV level that populates both members of the doublet. A positive correction amounting to 0.6 eV was made for the unobserved interband decay of the 29.19 keV state (29.19-->0 keV).
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Affiliation(s)
- B R Beck
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Skull SA, Andrews RM, Byrnes GB, Kelly HA, Nolan TM, Brown GV, Campbell DA. Pneumococcal Polysaccharide Vaccine May Not Prevent Hospitalization for Pneumonia in Elderly Individuals. Clin Infect Dis 2007. [DOI: 10.1086/510490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Brown GV, Beiersdorfer P, Chen H, Scofield JH, Boyce KR, Kelley RL, Kilbourne CA, Porter FS, Gu MF, Kahn SM, Szymkowiak AE. Energy-dependent excitation cross section measurements of the diagnostic lines of Fe XVII. Phys Rev Lett 2006; 96:253201. [PMID: 16907303 DOI: 10.1103/physrevlett.96.253201] [Citation(s) in RCA: 4] [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: 01/19/2005] [Indexed: 05/11/2023]
Abstract
By implementing a large-area, gain-stabilized microcalorimeter array on an electron beam ion trap, the electron-impact excitation cross sections for the dominant x-ray lines in the Fe XVII spectrum have been measured as a function of electron energy establishing a benchmark for atomic calculations. The results show that the calculations consistently predict the cross section of the resonance line to be significantly larger than measured. The lower cross section accounts for several problems found when modeling solar and astrophysical Fe XVII spectra.
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Affiliation(s)
- G V Brown
- University of California Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Buising KL, Thursky KA, Black JF, MacGregor L, Street AC, Kennedy MP, Brown GV. A prospective comparison of severity scores for identifying patients with severe community acquired pneumonia: reconsidering what is meant by severe pneumonia. Thorax 2006; 61:419-24. [PMID: 16449258 PMCID: PMC2111174 DOI: 10.1136/thx.2005.051326] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Several severity scores have been proposed to predict patient outcome and to guide initial management of patients with community acquired pneumonia (CAP). Most have been derived as predictors of mortality. A study was undertaken to compare the predictive value of these tools using different clinically meaningful outcomes as constructs for "severe pneumonia". METHODS A prospective cohort study was performed of all patients presenting to the emergency department with an admission diagnosis of CAP from March 2003 to March 2004. Clinical and laboratory features at presentation were used to calculate severity scores using the pneumonia severity index (PSI), the revised American Thoracic Society score (rATS), and the British Thoracic Society (BTS) severity scores CURB, modified BTS severity score, and CURB-65. The sensitivity, specificity, positive and negative predictive values were compared for four different outcomes (death, need for ICU admission, and combined outcomes of death and/or need for ventilatory or inotropic support). RESULTS 392 patients were included in the analysis; 37 (9.4%) died and 26 (6.6%) required ventilatory and/or inotropic support. The modified BTS severity score performed best for all four outcomes. The PSI (classes IV+V) and CURB had a very similar performance as predictive tools for each outcome. The rATS identified the need for ICU admission well but not mortality. The CURB-65 score predicted mortality well but performed less well when requirement for ICU was included in the outcome of interest. When the combined outcome was evaluated (excluding patients aged >90 years and those from nursing homes), the best predictors were the modified BTS severity score (sensitivity 94.3%) and the PSI and CURB score (sensitivity 83.3% for both). CONCLUSIONS Different severity scores have different strengths and weaknesses as prediction tools. Validation should be done in the most relevant clinical setting, using more appropriate constructs of "severe pneumonia" to ensure that these potentially useful tools truly deliver what clinicians expect of them.
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Affiliation(s)
- K L Buising
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia.
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