Neutron Time-of-Flight Ion Temperature Measurement of Direct-Drive Implosions on SG-II Laser Facility

摘要

A geometry-compensated shallow cup-shaped ST1422 plastic scintillator neutron time-of-flight(nTOF) detector has been designed and used on SG-II laser facility to diagnostic inertial confinement fusion(ICF) ion temperature in direct-drive implosions with yields of 10~8 approx 10~9 DT neutrons. The measurement system consists of a shallow cup-shaped ST1422 fast plastic scintillator with a thickness of 5mm and full effective volume of 170cm~3 placed at a distance of 5.25m from the target, a microchannel plate photomultiplier tube(MCP-PMT), a piece of coaxial cable(SUJ-50-7) with a length of 10m, and a transient oscilloscope with a bandwidth of 4.5GHz. The rise-time and FWHM of the temporal response function are 390ps and 1.47ns, respectively. Measured results for several shots are presented.