Implosion symmetry and {rho}{bold {ital R}} measurements on the National Ignition Facility from nascent 27{endash}31 MeV tertiary protons (invited) (abstract)
- MIT Plasma Fusion Center, Cambridge, Massachusetts 02139-0001 (United States)
Tertiary protons with birth energies from {approximately}27 to 30.8 MeV result from the implosion of ignition-scale inertial confinement fusion targets, such as those planned for the National Ignition Facility (NIF). Measurement of the tertiaries{close_quote} slowing can provide a determination of the imploded areal density of the fuel capsule, as well as implosion asymmetry that results from anisotropy of the areal density and plasma temperature. In order to determine the utility of tertiaries for all phases of the NIF, we analyze three representative cases: a gas capsule (0.7 kJ yield); a cryogenic fuel capsule that fails to ignite (15 kJ); and a cryogenic fuel capsule that ignites and burns (13000 kJ). In each case, tertiaries escape from the capsule and convey critical information about implosion dynamics. In addition, we show that for some gas-capsule implosions anticipated on OMEGA, tertiaries may be the only species of energetic charged particles that can determine the fuel areal density. Presently, we are building a charge-coupled device (CCD)-based charged particle spectrometer for OMEGA and for NOVA. In addition to the tertiaries, the spectrometers are sensitive to a variety of the energetic charged particles, such as knock-on protons, deuterons, and tritons, and {sup 3}He-burnup protons. In fact the latter set of charged particles will usually be the dominant signal. We will describe the basic features of the spectrometers and the measured response of the CCDs to 1{endash}5 MeV protons, 1{endash}5 MeV alphas, and 14 MeV neutrons (and associated gammas), the latter constitute the principal source of noise.
- OSTI ID:
- 453346
- Report Number(s):
- CONF-960543-; ISSN 0034-6748; TRN: 97:006588
- Journal Information:
- Review of Scientific Instruments, Vol. 68, Issue 1; Conference: 11. annual high-temperature plasma diagnostics conference, Monterey, CA (United States), 12-16 May 1996; Other Information: PBD: Jan 1997
- Country of Publication:
- United States
- Language:
- English
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