Experiments on plasma focus and DT microballoon interactions

Results have been obtained from initial experiments in which a small plasma focus was used to drive DT microballoons. The DT microballoons were 1 mm in diameter and contained 50 atmospheres of DT gas in a 50% mixture. The plasma focus driver achieves a maximum current of ∼ 1 MA from its 20-kV, 72-kJ capacitor bank. The plasma sheath was formed from deuterium, hydrogen, and helium for these tests. After several conditioning shots using the gas for the experiment, the microballoons were inserted into the focus region through an air lock in the device's anode, to avoid any electrical gradient between the positive electrode and the target. Neutron yields of 109 to 1010 14.1-MeV neutrons have been measured from the combination of a deuterium plasma sheath and a DT target. However, the authors have been unable to detect a significant DT-neutron yield with hydrogen and helium plasma sheaths. Therefore, one is led to conclude that the 14.1-MeV neutron yields that have been observed are due to a beam-target interaction between accelerated deuterons from the plasma sheath and the tritium gas in the microballoon. The results of these tests are presented