Speaker
Wenyi Huo
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.2004.pdf
Experimental investigation on spherical hohlraum energetics at the SG
laser facilities
W. Y. Huo1, Z. C. Li2, Y. H. Chen1, X. F. Xie2, G. L. Ren1, K. Lan1
1
Institute of Applied Physics and Computational Mathematics, Beijing, China
2
Research Centre of Laser Fusion, China Academy of Engineering Physics, Mianyang,
China
The integrated experiments at the National Ignition Facility indicate that the radiation
asymmetry control in the cylindrical hohlraums is an extremely challenging problem in
achieving ignition by using indirect drive. Recently, Lan et al. have proposed the octahedral
spherical hohlraum which has the natural superiority in providing high radiation symmetry.
As new and promising hohlraums, the octahedral spherical hohlraum attracts much research
interests. In indirect drive inertial confinement studies, hohlraum energetics is one of the
fundamental problems. In this presentation, we report on the spherical hohlraum experiments
performed at the SG series laser facilities. At the SGIII-prototype laser facility, we performed
the first spherical hohlraum energetics experiment. In this experiment, we used the vacuum
spherical hohlraum with 2 laser entrance holes. The radiation temperature is measured by
using an array of flat-response x-ray detectors (FXRDs) through a laser entrance hole at
different angles. The radiation temperature and M-band fraction inside the hohlraum are
determined by the shock wave technique. The experimental results show that there is no
intrinsic difference in energetics between spherical hohlraums and cylindrical hohlraums. At
the SGIII laser facility, we performed the first octahedral spherical hohlraum energetics
experiment. The 32 of 48 laser beams enter the hohlraum through six laser entrance holes.
We used 5 FXRDs to measure the radiation flux emitted from different regions inside the
octahedral spherical hohlraum. The radiation temperature inside the hohlraum is determined
by the shock wave technique. In this experiment, some interesting phenomena are observed
in the backscatter light induced by SRS.
