First Investigation on the Radiation Field of the Gas-Filled Three-Axis Cylindrical Hohlraum

TL;DR

This paper reports the first experimental investigation of the radiation field in a novel three-axis cylindrical hohlraum (TACH) designed for inertial confinement fusion, demonstrating its radiation characteristics and energy delivery efficiency.

Contribution

It presents the first experimental analysis of TACH's radiation field, providing insights into its energy delivery and plasma filling behavior for fusion applications.

Findings

Peak radiation temperature reached 192 eV.

Laser energy delivered effectively within 3 ns.

Gas filling did not significantly suppress plasma filling.

Abstract

A novel ignition hohlraum named three-axis cylindrical hohlraum (TACH) is designed for indirect-drive inertial confinement fusion. TACH is a kind of 6 laser entrance holes (LEHs) hohlraum, which is orthogonally jointed of three cylindrical hohlraums. The first experiment on the radiation field of TACH was performed on Shenguang III laser facility. 24 laser beams were elected and injected into 6 LEHs quasi-symmetrically. Total laser energy was about 59 kJ, and the peak radiation temperature reached about 192 eV. Radiation temperature and pinhole images in gas-filled hohlraum are largely identical but with minor differences with those in vacuum hohlraum. All laser energy can be totally delivered into hohlraum in 3 ns duration even without filled gas in the hohlraum of 1.4 mm diameter. Plasma filling cannot be obviously suppressed even with 0.5 atm pressure gas in the small hohlraum. Backscattering fractions of vacuum hohlraum and gas-filled hohlraum are both lower than 2%. Experimental study of this new kind of hohlraum can provide guidance for future target design and implosion experiment.