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Title: Computer simulations of laser hot spots and implosion symmetry kiniform phase plate experiments on Nova

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.873974· OSTI ID:20216037
 [1];  [2];  [2];  [2]
  1. Fusion Technology Institute, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706 (United States)
  2. Los Alamos National Laboratory, MS B220, Los Alamos, New Mexico 87545 (United States)

LASNEX computer code simulations have been performed for radiation symmetry experiments on the Nova laser with vacuum and gas-filled hohlraum targets [R. L. Kauffman et al., Phys. Plasmas 5, 1927 (1998)]. In previous experiments with unsmoothed laser beams, the symmetry was substantially shifted by deflection of the laser beams. In these experiments, laser beams have been smoothed with Kiniform Phase Plates in an attempt to remove deflection of the beams. The experiments have shown that this smoothing significantly improves the agreement with LASNEX calculations of implosion symmetry. The images of laser produced hot spots on the inside of the hohlraum case have been found to differ from LASNEX calculations, suggesting that some beam deflection or self-focusing may still be present or that emission from interpenetrating plasmas is an important component of the images. The measured neutron yields are in good agreement with simulations for vacuum hohlraums but are far different for gas-filled hohlraums. (c) 2000 American Institute of Physics.

OSTI ID:
20216037
Journal Information:
Physics of Plasmas, Vol. 7, Issue 5; Other Information: PBD: May 2000; ISSN 1070-664X
Country of Publication:
United States
Language:
English