The investigation of spherically convergent plasma fusion as a high-flux neutron source with a long-pulsed laser driving

Abstract

The spherically convergent plasma fusion (SCPF) scheme is a robust approach to provide a high-brightness pulsed neutron source. The performance of the SCPF driven by the long-pulsed laser is investigated. The experiments, with the laser pulse duration in a range of 0.5ns to 3ns, were implemented on ShenGuang-II Upgrade facility and a 100kJ level laser facility. The intensity of the laser beam was about multiple 1014W/cm2. The measured D-D reaction neutron yields were in a range of 7.3×108 to 1.01×1011, while the driven laser energies were in a range of 2.1kJ to 100.5kJ. The temporal self-emitted X-ray flux and image were measured. They shew that the plasma core could be maintained for a longer time in the long duration shots. The neutron reaction rate was measured on the 100kJ level laser facility. The full width at half maximum (FWHM) reached about 1ns in the shot with 2ns duration laser. The scaling law of the measured yields respect to the laser power and the pulse duration were presented. The neutron yield was possible to be increased by increasing the power and extending the duration.