Spiral wobbling beam illumination uniformity in Heavy Ion Fusion
Abstract
A new beam illumination scheme has been found, in which a few per cent beam illumination nonuniformity is realized for a spiraling and ``wobbling'' beam in a heavy ion inertial confinement fusion (HIF) driver. The oscillating-HIB (heavy ion beam) energy deposition may produce a time-dependent implosion acceleration, which reduces both the Rayleigh-Taylor (R-T) growth [NIMA 606, 152(2009)] and the implosion nonuniformity. Three-dimensional HIB illumination computations indicate that the few per cent spiral-wobbling HIB illumination nonuniformity oscillates with the same wobbling HIB frequency. In HIF, HIB axes can be controlled precisely with a high frequency (100MHz ~ 1GHz) centroid oscillation about the axis. This oscillating HIB creates a small oscillating energy deposition in time and space. This small oscillating nonuniformity can produce a small oscillating implosion acceleration nonuniformity. When the oscillation frequency is comparable to or larger than the R-T growth rate, it reduces the R-T growth significantly.
This work is partly supported by MEXT, JSPS, ILE/Osaka Univ. and CORE (Center for Optical Research and Education, Utsunomiya Univ., Japan).- Publication:
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APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2011
- Bibcode:
- 2011APS..DPPGP9112K