Laser propagation in a gas-filled target with 0.53 and 0.35 {mu}m at various electron densities on Nova
- Lawrence Livermore National Lab., CA (United States)
Thin-walled gas-filled targets have been irradiated with the Nova laser in order to measure laser propagation into a gas to form a plasma with electron density ranging from 0.05--0.25 n{sub c}. The targets consist of a thin (0.6--1.0 {mu}m) polyimide skin that is stretched across the two faces of a washer, and then inflated to hold 1 atmosphere of gas. The experiments were done with {le} 1 atmosphere of neopentane (3 mg/cm{sup 3}). Additional shots were done to propagate a Nova beam into a preformed plasma by using two opposing beams with a relative delay. Peak laser irradiance on the target was varied from 3 {times} 10{sup 14} to 6 {times} 10{sup 15} W/cm{sup 2}. The beam propagation into the gas was measured from streaked and gated x-ray images taken normal to the direction of laser propagation. Plasma temperature was measured spectroscopically with dopants in the gas-fill mixture. The effect of phase plates and SSD on beam propagation into the gas were studied using an f/4 and an f/8 laser beam on Nova. Lateral heat flow was also measured from the gated x-ray imaging. The propagation of the laser burn-front is compared to LASNEX calculations. A mm-scale plasma is created at approximately 1--1.5 keV with 2--3 kJ of laser energy delivered to the target in a 1 ns square-profile pulse.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 42959
- Report Number(s):
- CONF-940604-; ISBN 0-7803-2006-9; TRN: IM9521%%123
- Resource Relation:
- Conference: 1994 Institute of Electrical and Electronic Engineers (IEEE) international conference on plasma science, Santa Fe, NM (United States), 6-8 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of IEEE conference record -- Abstracts; PB: 252 p.
- Country of Publication:
- United States
- Language:
- English
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