Faeton-I: Investigation of plasma dynamics and radiation output of a 100 kV plasma focus device

Faeton-I (F-I) is the highest direct-charged voltage plasma focus (PF), at 100 kV, 1 MA peak current. F-I produces consistent 2.5×1010 D-D neutrons/shot, over 3 MeV X-rays and ~350 keV deuterons, demonstrating unique combined neutron-gamma environment. Its peak neutron yield was recorded at 8×1010 neutrons/shot at 12 torr deuterium. The overall best peak dynamics-induced pinch voltage of the F-I was measured at 194 kV. A major difficulty anticipated for PF operation at high-voltage and high-current is the likelihood of re-strikes which divert current away from the compressing plasma. F-I shows excellent current sheath dynamics and above-scaling D-D neutron yield, despite severe re-strikes. This study, correlating current and voltage time profiles with radial trajectories, reveals that the dynamics-induced voltage peak of ~150 kV, produces the deuteron beam first, then the re-strikes, which do not affect the target pinch plasma in geometry and areal density. Thus, this first neutron pulse is unaffected by re-strikes, and the very high-voltage results in above-scaling out-performance, despite degradation of the second neutron pulse from pinch instabilities. The first pulse at 100-200 keV (peak D-T cross section) ion energy, completely dominates the second pulse with micro-beams at MeV (low D-T cross section).