Results and plan of research of plasma compression and total D-D fusion neutron emission for 16.8-kJ and 3.1-kJ plasma foci operated with D₂, D₂+Ne and D₂+Ar gas mixtures

A total of 269 discharges were performed on the 16.8-kJ Mather-type plasma focus device (called PF-24) filled with D₂ and (100%-x)D₂+xNe at a constant, initial, total mass of gas mixture in the experimental chamber. Magnetic and electric probes, Be activation neutron counter and 4-frame VUV/SXR plasma imaging system were used to study the plasma dynamics and radiation emission. The results showed a decrease in the radii of plasma columns (on average) in the initial phase of evolution and a decrease in the total D-D fusion neutron yields (on average) with increasing Ne fraction (x). Presently, similar new set of experiments is being planned and carried for the 3.1-kJ Mather-type plasma focus (called PFZ-200) which will operate with D₂ and (100%-x)D₂+xAr at the constant initial mass of deuterium in the mixture or at the constant initial total mass of gas mixture. For both PF-24 and PFZ-200 the 5-phase Lee model was used to design the discharges – chose the proper gas mixture composition and make predictions about the possible phenomena accompanying discharges. The main aims of these investigations are enhancement of plasma pinch compression and increase the total D-D fusion neutron emission, in plasma foci, by doping deuterium with noble gases.