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Background measurement methods for opacity experiments conducted at the Z facility

Review of Scientific Instruments

Dunham, Gregory S.; Nagayama, Taisuke N.; Bailey, James E.; Loisel, Guillaume P.

Laboratory experiments typically test opacity models by measuring spectrally resolved transmission of a sample using bright backlight radiation. A potential problem is that any unaccounted background signal contaminating the spectrum will artificially reduce the inferred opacity. Methods developed to measure background signals in opacity experiments at the Sandia Z facility are discussed. Preliminary measurements indicate that backgrounds are 9%–11% of the backlight signal at wavelengths less than 10 Å. Background is thus a relatively modest correction for all Z opacity data published to date. Future work will determine how important background is at longer wavelengths.

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TYPE Journal Article YEAR 2021
OSTIDOI

Narrowband Self-Emission X-ray Imaging of MagLIF Targets on Z

Gomez, Matthew R.; Fein, Jeffrey R.; Hansen, Stephanie B.; Harvey-Thompson, Adam J.; Dunham, Gregory S.; Knapp, Patrick K.; Slutz, Stephen A.; Weis, Matthew R.; Jennings, Christopher A.; Robertson, Grafton K.; Speas, Christopher S.; Maurer, A.; Ampleford, David A.; Rochau, G.A.; Doron, R.D.; O. Nedostup, E.O.; Stambulchik, Stambulchik; Zarnitsky, Y.Z.; Maron, Y.M.; Paguio, Reny P.; Tomlinson, Kurt T.; Huang, H.H.; Smith, Gary S.; Taylor, Randy T.

Abstract not provided.

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TYPE Conference Presenation YEAR 2020
OSTIDOI

A Wolter Imager on the Z Machine to Diagnose Warm X-ray Sources

Ampleford, David A.; Fein, Jeffrey R.; Vogel, J.K.V.; Kozioziemski, B.J.; Walton, C.C.W.; Wu, Ming W.; Ball, Christopher R.; A. Ames, J.A.; Bell, P.B.; Bourdon, Christopher B.; D. Bradley, R.B.; Dunham, Gregory S.; Gard, Paul D.; Johnson, Drew J.; Kilaru, K.K.; Lake, Patrick W.; Maurer, A.; Nielsen-Weber, Linda B.; Pickworth, L.A.; Pivovaroff, M.J.; Ramsey, B.R.; Roberts, O.J.R.; Sullivan, Michael A.; Rochau, G.A.

Abstract not provided.

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TYPE Presentation YEAR 2018
OSTI

Engineering Design for Wolter Imaging Diagnostic on Z

Ball, Christopher R.; Ampleford, David A.; Gard, Paul D.; Maurer, A.; Bourdon, Christopher B.; Fein, Jeffrey R.; Wu, Ming W.; Lake, Patrick W.; Nielsen-Weber, Linda B.; Dunham, Gregory S.; Johnson, Drew J.; Johns, Owen J.; Sullivan, Michael A.; Kirtley, Christopher K.; Kozioziemski, B.J.; Pickworth, L.A.P.; Vogel, J.K.V.; Pivovaroff, M.JP.; Walton, C.C.W.; Ayers, J.A.; Bell, P.B.; Ramsey, B.R.; Romaine, S.R.

Abstract not provided.

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TYPE Conference Poster YEAR 2018
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Cross-calibration of Fuji TR image plate and RAR 2492 x-ray film to determine the response of a DITABIS Super Micron image plate scanner

Review of Scientific Instruments

Dunham, Gregory S.; Harding, Eric H.; Loisel, G.P.; Lake, P.W.; Nielsen-Weber, Linda B.

Fuji TR image plate is frequently used as a replacement detector medium for x-ray imaging and spectroscopy diagnostics at NIF, Omega, and Z facilities. However, the familiar Fuji BAS line of image plate scanners is no longer supported by the industry, and so a replacement scanning system is needed. While the General Electric Typhoon line of scanners could replace the Fuji systems, the shift away from photo stimulated luminescence units to 16-bit grayscale Tag Image File Format (TIFF) leaves a discontinuity when comparing data collected from both systems. For the purposes of quantitative spectroscopy, a known unit of intensity applied to the grayscale values of the TIFF is needed. The DITABIS Super Micron image plate scanning system was tested and shown to potentially rival the resolution and dynamic range of Kodak RAR 2492 x-ray film. However, the absolute sensitivity of the scanner is unknown. In this work, a methodology to cross calibrate Fuji TR image plate and the absolutely calibrated Kodak RAR 2492 x-ray film is presented. Details of the experimental configurations used are included. An energy dependent scale factor to convert Fuji TR IP scanned on a DITABIS Super Micron scanner from 16-bit grayscale TIFF to intensity units (i.e., photons per square micron) is discussed.

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TYPE Conference Poster YEAR 2016
ScopusOSTIDOI

Signatures of hot electrons and fluorescence in Mo Kα emission on Z

Physics of Plasmas

Hansen, Stephanie B.; Ampleford, David A.; Cuneo, M.E.; Ouart, N.; Jones, Brent M.; Jennings, C.A.; Dasgupta, A.; Coverdale, Christine A.; Rochau, G.A.; Dunham, Gregory S.; Giuliani, J.L.; Apruzese, J.P.

Recent experiments on the Z accelerator have produced high-energy (17 keV) inner-shell K-alpha emission from molybdenum wire array z-pinches. Extensive absolute power and spectroscopic diagnostics along with collisional-radiative modeling enable detailed investigation into the roles of thermal, hot electron, and fluorescence processes in the production of high-energy x-rays. We show that changing the dimensions of the arrays can impact the proportion of thermal and non-thermal K-shell x-rays. © 2014 AIP Publishing LLC.

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TYPE Conference YEAR 2014
ScopusOSTI
Results 1–25 of 33
Results 1–25 of 33