Effect of anode shapes on neutron emission from a repetitive plasma focus device

The conventional tapered anode of the NX2 repetitive plasma focus device has been changed to two other shapes (straight and spherical) to investigate the effect of anode shape on neutron emission characteristics of the device. The newly designed beryllium counter and ³He proportional counter are used for estimation of neutron yield and time resolved neutron emission characteristics are measured using two PMT based plastic scintillator detectors located at different radial distances from the anode axis. It is found that the straight anode mostly produces multiple neutron peaks, the spherical anode on the other hand essentially has a single neutron peak in its signal while the tapered anode has a mixed behavior. It is found that there is no significant difference in the average neutron yield (typically of the order of 10⁷ neutrons per shot) for different anode shapes. However the pressure at which the maximum neutron yield occurs depends on the anode shape. The anode with spherical tip shows the most stable neutron emission with consistently good neutron yield over a much wider pressure range than the other anode shapes.