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Title: Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations

Abstract

This paper reports on synthetic transmission results from Lasnex [1] radiation-hydrodynamics simulations of opacity experiments carried out at Sandia National Laboratories' recently upgraded ZR facility. The focus is on experiments utilizing disk targets composed of a half-moon Fe/Mg mixture tamped on either end with 10- m CH and an additional 35- m beryllium tamper accessory on the end facing the spectrometer. Five x-ray sources with peak power ranging from 10 to 24 TW were used in the simulations to heat and backlight the opacity target. The dominant effect is that the beryllium behind the Fe/Mg mixture is denser and more opaque than the beryllium unshielded by metal during the times of greatest importance for the transmission measurement for all drives. This causes the simulated transmission to be lower than expected, and this is most pronounced for the case using the lowest drive power. While beryllium has a low opacity, its areal density is sufficiently high such that the expected reduction of the measured transmission is significant. This situation leads to an overestimate of iron opacity by 10-215% for a photon energy range of 975- 1775 eV for the 10-TW case. It is shown that if the tamper conditions are known,more » the transmission through each component of the target can be calculated and the resulting opacity can be corrected.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1];  [1];  [1];  [1];  [1]; ORCiD logo [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1402644
Alternate Identifier(s):
OSTI ID: 1380048
Report Number(s):
LA-UR-17-25291
Journal ID: ISSN 1070-664X; TRN: US1703119
Grant/Contract Number:
AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 9; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Morris, H. E., Tregillis, I. L., Hoffman, N. M., Sherrill, M. E., Fontes, C. J., Marshall, A. J., Urbatsch, T. J., and Bradley, P. A. Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations. United States: N. p., 2017. Web. doi:10.1063/1.4994062.
Morris, H. E., Tregillis, I. L., Hoffman, N. M., Sherrill, M. E., Fontes, C. J., Marshall, A. J., Urbatsch, T. J., & Bradley, P. A. Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations. United States. doi:10.1063/1.4994062.
Morris, H. E., Tregillis, I. L., Hoffman, N. M., Sherrill, M. E., Fontes, C. J., Marshall, A. J., Urbatsch, T. J., and Bradley, P. A. Tue . "Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations". United States. doi:10.1063/1.4994062.
@article{osti_1402644,
title = {Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations},
author = {Morris, H. E. and Tregillis, I. L. and Hoffman, N. M. and Sherrill, M. E. and Fontes, C. J. and Marshall, A. J. and Urbatsch, T. J. and Bradley, P. A.},
abstractNote = {This paper reports on synthetic transmission results from Lasnex [1] radiation-hydrodynamics simulations of opacity experiments carried out at Sandia National Laboratories' recently upgraded ZR facility. The focus is on experiments utilizing disk targets composed of a half-moon Fe/Mg mixture tamped on either end with 10- m CH and an additional 35- m beryllium tamper accessory on the end facing the spectrometer. Five x-ray sources with peak power ranging from 10 to 24 TW were used in the simulations to heat and backlight the opacity target. The dominant effect is that the beryllium behind the Fe/Mg mixture is denser and more opaque than the beryllium unshielded by metal during the times of greatest importance for the transmission measurement for all drives. This causes the simulated transmission to be lower than expected, and this is most pronounced for the case using the lowest drive power. While beryllium has a low opacity, its areal density is sufficiently high such that the expected reduction of the measured transmission is significant. This situation leads to an overestimate of iron opacity by 10-215% for a photon energy range of 975- 1775 eV for the 10-TW case. It is shown that if the tamper conditions are known, the transmission through each component of the target can be calculated and the resulting opacity can be corrected.},
doi = {10.1063/1.4994062},
journal = {Physics of Plasmas},
number = 9,
volume = 24,
place = {United States},
year = {Tue Aug 01 00:00:00 EDT 2017},
month = {Tue Aug 01 00:00:00 EDT 2017}
}

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