First Integrated Implosion Experiment of Three-Axis Cylindrical Hohlraum at the SGIII Laser Facility

TL;DR

This paper reports the first successful integrated implosion experiment of a three-axis cylindrical hohlraum at the SGIII laser facility, demonstrating its symmetry, radiation temperature, and neutron yield performance.

Contribution

It is the first experimental demonstration of the TACH design's symmetry and performance characteristics at a major laser facility.

Findings

Achieved a peak radiation temperature of ~190 eV.

Neutron yield reached ~1×10^9 with a yield over clean of ~40%.

Laser backscatter fraction was less than 1.25%.

Abstract

The first integrated implosion experiment of three-axis cylindrical hohlraum (TACH) was accomplished at the SGIII laser facility. 24 laser beams of the SGIII laser facility were carefully chosen and quasi-symmetrically injected into the TACH, in which a highly symmetric radiation filed was generated with a peak radiation temperature of ~190eV. Driven by the radiation field, the neutron yield of a deuterium gas filled capsule reached ~1e9, and the corresponding yield over clean (YOC) was ~40% for a convergence ratio (Cr) of ~17. The X-ray self-emission image of imploded capsule cores was nearly round, and the backscatter fraction of laser beams was less than 1.25%. This experiment preliminarily demonstrated the major performance of TACH, such as the robustness of symmetry, and a laser plasma instability (LPI) behavior similar to that of the outer ring of traditional cylindrical hohlraum.