No abstract

No abstract

2016-11-03T14:11:40

In this work, the developed spherical plasma focus model is used to investigate the effect of the cathode radius on the plasma dynamics and radiation emissions. The cathode radius is varied from 11.5 cm to 17 cm with 0.5 cm increment, and the results are reported in this paper for the spherical plasma focus with 8 cm inner electrode (anode) radius. While discharge current and voltage, plasma and shock velocities, and radiation emissions are found to be higher for short cathode radius, plasma resistance increases with increasing cathode radius. This study also shows that the optimum cathode radius for plasma dynamics and radiation emissions is 15 cm for the used spherical plasma focus device.

The developed spherical plasma focus model is used in this study to investigate the optimum neutron yield in terms of the gas pressure, cathode radius and external inductance. The optimum values for these parameters are found separately. Then, the charging voltage is varied from 25[Formula: see text]kV to 35[Formula: see text]kV with 1[Formula: see text]kV increment by using these separately found optimum values to see the rate of increase in neutron yield. While the used gas pressure range is 1–40[Formula: see text]Torr with 1[Formula: see text]Torr increment, cathode radius range is 11.5–17[Formula: see text]cm with 0.5[Formula: see text]cm increment. External inductance is varied from 10[Formula: see text]nH to 150[Formula: see text]nH with 5[Formula: see text]nH increment. The optimum values for gas pressure, cathode radius and external inductance are found to be 26[Formula: see text]Torr, 15[Formula: see text]cm and 75[Formula: see text]nH, respectively. Even though combining these separately found optimum values of pressure, cathode radius and external inductance does not necessarily form an optimized set of operational conditions for the SPF, they lead to a higher neutron yield in that while neutron yield with these separately found optimum values at 25[Formula: see text]kV charging voltage is [Formula: see text] (higher than the measured neutron yield of [Formula: see text] at 25[Formula: see text]kV), it increases to [Formula: see text], when charging voltage is increased to 35[Formula: see text]kV. Using these values shows that spherical plasma focus device can be used as a neutron source with high neutron yield (on the order of [Formula: see text]).