Diagnosis of pusher-fuel mix in spherical implosions using x-ray spectroscopy (invited)

Journal Article · Sun Jan 01 00:00:00 EST 1995 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1146260· OSTI ID:6698663

Keane, C J; Cook, R C; Dittrich, T R; Hammel, B A; Levedahl, W K; Landen, O L; Langer, S; Munro, D H; Scott, H A ^[1]

---

1. Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (United States)

Of primary concern in next generation inertial confinement fusion (ICF) implosion experiments is Rayleigh--Taylor (RT) instability of the pusher-fuel interface occurring upon acceleration and deceleration of the pusher. This results in mixing of hot fuel with cold pusher material. One method of diagnosing mix in this case is to place spectroscopic dopants both in the capsule fuel region and the innermost region of the capsule wall adjacent to the fuel. As the degree of pusher/fuel mix is increased (typically through placement of controlled perturbations on the outer surface of the capsule) the pusher dopant x-ray emission increases relative to that of the fuel dopant. Experiments of this type using indirectly driven implosions have been carried out on Nova. In this paper we describe some of the important physics issues underlying spectral line formation in these targets and discuss how they are manifested in the modeling and interpretation of experimental data. The importance of radiative transfer as well as high density plasma phenomena such as continuum lowering and Stark broadening is demonstrated. We provide an overview of recent Nova hydrodynamic instability experiments and discuss how the level of instability growth implicit in a given capsule design impacts the diagnosis of mix through x-ray spectroscopy.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6698663
• Journal Information: Review of Scientific Instruments; (United States), Vol. 66:1; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
LASER IMPLOSIONS
RAYLEIGH-TAYLOR INSTABILITY
PLASMA DIAGNOSTICS
X-RAY SPECTROSCOPY
INSTABILITY GROWTH RATES
LASER TARGETS
NOVA FACILITY
IMPLOSIONS
INSTABILITY
SPECTROSCOPY
TARGETS
700411* - Inertial Confinement Devices- (1992-)
700320 - Plasma Diagnostic Techniques & Instrumentation- (1992-)
700340 - Plasma Waves
Oscillations
& Instabilities- (1992-)