Use of d-{sup 3}He proton spectroscopy as a diagnostic of shell {rho}r in capsule implosion experiments with {approx}0.2 NIF scale high temperature Hohlraums at Omega
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- L.L.E., University of Rochester, Rochester, New York 14627 (United States)
- M.I.T., Cambridge, Massachusetts 02139-4307 (United States)
We present the calculations and preliminary results from experiments on the Omega laser facility using d-{sup 3}He filled plastic capsule implosions in gold Hohlraums. These experiments aim to develop a technique to measure shell {rho}r and capsule unablated mass with proton spectroscopy and will be applied to future National Ignition Facility (NIF) experiments with ignition scale capsules. The Omega Hohlraums are 1900 {mu}m lengthx1200 {mu}m diameter and have a 70% laser entrance hole. This is approximately a 0.2 NIF scale ignition Hohlraum and reaches temperatures of 265-275 eV similar to those during the peak of the NIF drive. These capsules can be used as a diagnostic of shell {rho}r, since the d-{sup 3}He gas fill produces 14.7 MeV protons in the implosion, which escape through the shell and produce a proton spectrum that depends on the integrated {rho}r of the remaining shell mass. The neutron yield, proton yield, and spectra change with capsule shell thickness as the unablated mass or remaining capsule {rho}r changes. Proton stopping models are used to infer shell unablated mass and shell {rho}r from the proton spectra measured with different filter thicknesses. The experiment is well modeled with respect to Hohlraum energetics, neutron yields, and x-ray imploded core image size, but there are discrepancies between the observed and simulated proton spectra.
- OSTI ID:
- 21266515
- Journal Information:
- Review of Scientific Instruments, Vol. 79, Issue 10; Other Information: DOI: 10.1063/1.2978198; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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