Hot Electron and Ion Spectra in Axial and Transverse Laser Irradiation in the GXII-LFEX Direct Fast Ignition Experiment

Abstract

An electron spectrometer was used to measure the electron and ion spectra in two different irradiations of implosion laser to the deuterated spherical shell targets at the direct fast ignition experiments on the Gekko-LFEX facility. In the transverse irradiation against the LFEX laser axis, the low effective hot electron temperature (T_eff) and huge neutron yield (Ny) could be obtained although high T_eff and low Ny could be observed in the axial irradiation. In the transverse irradiation, the efficient core heating could be obtained because the laser-plasma interaction position is close to the core and the diffusive/ion drag heating may be effective.