Neutron Energy Distribution Function Reconstructed From Time-of-Flight Signals in Deuterium Gas-Puff Z-Pinch

The implosion of a solid deuterium gas-puff Z-pinch was studied on the S-300 pulsed power generator [A. S. Chernenko, et al, Proceedings of 11th Int. Conf. on High Power Particle Beams, 154 (1996)]. The peak neutron yield above 10(10) was achieved on the current level of 2 MA. The fusion neutrons were generated at about 150 ns after the current onset, i.e., during the stagnation and at the beginning of the expansion of a plasma column. The neutron emission lasted on average 25 ns. The neutron energy distribution function was reconstructed from 12 neutron time-of-flight signals by the Monte Carlo simulation. The side-on neutron energy spectra peaked at 2.42 +/- 0.04 MeV with about 450-keV FWHM. In the downstream direction (i.e., the direction of the current flow from the anode toward the cathode), the peak neutron energy and the width of a neutron spectrum were 2.6 +/- 0.1 MeV and 400 keV, respectively. The average kinetic energy of fast deuterons, which produced fusion neutrons, was about 100 keV. The generalized beam-target model probably fits best to the obtained experimental data.