ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
In inertial confinement fusion (ICF), the energy deposition of, first, heavy ions in the hohlraum and, second, charged fusion products in the plasma pellet is an essential issue. This can be quite subtle because the targets experience a series of phase transitions (solid→gas→partially ionized plasma→fully ionized plasma) and, most importantly, charged particle energy deposition depends on whether the charged particles are in the "fast,'' "intermediate,'' or "slow'' regime, which depends on the plasma temperature. (The regime is defined as xi/e=vi2/vthe2. vi is ion velocity and vthe is electron thermal velocity. xi/e(very-much-greater-than)1, xi/e∼1, and xi/e(very-much-less-than)1 correspond to fast, intermediate, and slow regimes, respectively.) A physical model based on the theory of binary interactions and plasma collective effects is being applied to the stopping power in these different regimes, especially in the transition regime (xi/e∼1), which is almost always ignored. From this model, we describe the physical picture of the evolution in energy deposition in both holhraum and the compressed pellet. Taking the typical ICF parameters for holhraum−ion energy ∼1 MeV/amu, electron density ∼1024 cm−3, and plasma temperature from a few eV to 1 keV −the scale sizes for both collisional energy exchange and electron plasma wave damping have been estimated and the energy relaxation rates of both mechanisms calculated. The significance of nuclear stopping and electron degeneracy effects will also be considered for fusion products in the core of pellet plasma. Finally, we briefly extend this model to the Solar core. This work was supported by U. S. Department of Energy Grant No. DE-FG02-91ER54109 and LLNL Subcontract B116798.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1143579
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