Recent progress of implosion experiments with uniformity-improved GEKKO XII laser facility at the Institute of Laser Engineering, Osaka University
- Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka, 565 (Japan)
The irradiation uniformity of the GEKKO XII laser [C. Yamanaka {ital et} {ital al}., IEEE J. Quantum Electron. {bold QE-17} 1639 (1981)] has been improved by using partially coherent light with angular spectral dispersion and by improving power balance among the beams. Implosion experiments with the uniformity-improved GEKKO XII have been carried out in order to demonstrate stable formation of the hot spark. The isentrope of the compressed pellet shell is controlled by adding a prepulse to enhance the ablative stabilization of the Rayleigh{endash}Taylor instability. The implosion dynamics has been investigated by x-ray imaging and neutron diagnostics. The experimental results are compared with the mix model prediction based on the one-dimensional hydrodynamic simulation. The degradation of neutron yield is attributed to the low-mode asymmetry. Finally, recent results of planer target experiments on the ablative stabilization of the Rayleigh{endash}Taylor instability are also presented. The observed linear growth rate was about 50{percent} of the classical growth rate and was lower than that of the theoretical prediction, based on the Takabe formula combined with the one-dimensional simulation. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 282910
- Journal Information:
- Physics of Plasmas, Vol. 3, Issue 5; Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
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