skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Development of Compton radiography of inertial confinement fusion implosions

Abstract

An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60 to 200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The radiographs have a spatial and temporal resolution of {approx}10 {mu}m and {approx}10 ps, respectively. A statistical accuracy of {approx}0.5% in transmission per resolution element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D nonuniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.

Authors:
; ; ; ; ; ; ; ;  [1]; ; ; ;  [2]
  1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
  2. Laboratory of Laser Energetics, Rochester, New York 14623-1299 (United States)
Publication Date:
OSTI Identifier:
21537894
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 18; Journal Issue: 5; Other Information: DOI: 10.1063/1.3567499; (c) 2011 American Institute of Physics
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COMPTON EFFECT; IMAGES; INERTIAL CONFINEMENT; PLASMA DIAGNOSTICS; PLASMA INSTABILITY; BASIC INTERACTIONS; CONFINEMENT; ELASTIC SCATTERING; ELECTROMAGNETIC INTERACTIONS; INSTABILITY; INTERACTIONS; PLASMA CONFINEMENT; SCATTERING

Citation Formats

Tommasini, R., Hatchett, S. P., Hey, D. S., Iglesias, C., Izumi, N., Koch, J. A., Landen, O. L., MacKinnon, A. J., Sorce, C., Delettrez, J. A., Glebov, V. Yu., Sangster, T. C., and Stoeckl, C. Development of Compton radiography of inertial confinement fusion implosions. United States: N. p., 2011. Web. doi:10.1063/1.3567499.
Tommasini, R., Hatchett, S. P., Hey, D. S., Iglesias, C., Izumi, N., Koch, J. A., Landen, O. L., MacKinnon, A. J., Sorce, C., Delettrez, J. A., Glebov, V. Yu., Sangster, T. C., & Stoeckl, C. Development of Compton radiography of inertial confinement fusion implosions. United States. doi:10.1063/1.3567499.
Tommasini, R., Hatchett, S. P., Hey, D. S., Iglesias, C., Izumi, N., Koch, J. A., Landen, O. L., MacKinnon, A. J., Sorce, C., Delettrez, J. A., Glebov, V. Yu., Sangster, T. C., and Stoeckl, C. Sun . "Development of Compton radiography of inertial confinement fusion implosions". United States. doi:10.1063/1.3567499.
@article{osti_21537894,
title = {Development of Compton radiography of inertial confinement fusion implosions},
author = {Tommasini, R. and Hatchett, S. P. and Hey, D. S. and Iglesias, C. and Izumi, N. and Koch, J. A. and Landen, O. L. and MacKinnon, A. J. and Sorce, C. and Delettrez, J. A. and Glebov, V. Yu. and Sangster, T. C. and Stoeckl, C.},
abstractNote = {An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60 to 200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The radiographs have a spatial and temporal resolution of {approx}10 {mu}m and {approx}10 ps, respectively. A statistical accuracy of {approx}0.5% in transmission per resolution element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D nonuniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.},
doi = {10.1063/1.3567499},
journal = {Physics of Plasmas},
number = 5,
volume = 18,
place = {United States},
year = {Sun May 15 00:00:00 EDT 2011},
month = {Sun May 15 00:00:00 EDT 2011}
}
  • An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60-200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton Radiography technique to the study of the final compression of directly driven plastic capsules at the OMEGA facility. The radiographs have a spatial and temporal resolution of {approx}10 {micro}m and {approx}10ps, respectively. A statistical accuracy of {approx}0.5% in transmission per resolutionmore » element is achieved, allowing localized measurements of areal mass densities to 7% accuracy. The experimental results show 3D non-uniformities and lower than 1D expected areal densities attributed to drive asymmetries and hydroinstabilities.« less
  • We present scaled demonstrations of backlighter sources, emitting bremsstrahlung x rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the bremsstrahlung spectrum as a function of laser intensity and pulse length from solid targets irradiated at 2x10{sup 17}-5x10{sup 18} W/cm{sup 2} using 2-40 ps pulses. Using Au planar foils we achieved source sizes down to 5.5 {mu}mmore » and conversion efficiencies of about 1x10{sup -13} J/J into x-ray photons with energies in the 75-100 keV spectral range. We can now use these results to design NIF backlighter targets and shielding and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.« less
  • We present scaled demonstrations of backlighter sources, emitting Bremsstrahlung x-rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the Bremsstrahlung spectrum as a function of laser intensity and pulse length, from solid targets irradiated at 2e17-5e18 W/cm{sup 2} using 2-40 ps pulses. Using Au planar foils we achieved source sizes down to 5.5 {micro}m, and conversion efficienciesmore » of about 1e-3 J/J into x-ray photons with energies in the 75-100 keV spectral range. We can now use these results to design NIF backlighter targets and shielding, and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.« less
  • An important diagnostic tool for inertial confinement fusion is time-resolved imaging of the dense cold fuel surrounding the hot spot. Here we report on the source and diagnostic development of hard x-ray radiography and on the first radiographs of direct drive implosions obtained at photon energies up to about 100keV, where the Compton effect is the dominant contributor to the shell opacity. The radiographs of direct drive, plastic shell implosions obtained at the OMEGA laser facility have a spatial resolution of {approx}10um and a temporal resolution of {approx}10ps. This novel Compton Radiography is an invaluable diagnostic tool for Inertial Confinementmore » Fusion targets, and will be integrated at the National Ignition Facility (NIF).« less
  • The first measurements and numerical simulations of fusion neutrons from the gas{endash}pusher interface of indirectly-driven inertial confinement fusion implosions have been performed using hydrogen-filled capsules made with a deuterated inner layer. Nonlinear saturation of the growth of hydrodynamic perturbations in high linear growth factor ({approx_equal}325) implosions was varied by adjusting the initial surface roughness of the capsule. The neutron yields are in quantitative agreement with the direct simulations of perturbation growth, and also with a linear mode superposition and saturation model including enhanced thermal loss in the mixed region. Neutron spectra from these capsules are broader than expected for themore » calculated ion temperatures, suggesting the presence of nonthermal broadening from mass motion during the fusion burn. {copyright} {ital 1998 American Institute of Physics.}« less