Investigation of gas-puffed discharges of the plasma-focus type

Summary Form only given, as follows. The influence of the initial gas distribution on plasma focus (PF) formation has been investigated using a modified MAJA-PF facility operating under different static and dynamic initial gas conditions. For the static pressure mode all the characteristics of the PF discharges are very similar to those observed for the standard PF facility. For the gas-puffed operation the discharge current converts an annular cloud of deuterium into a plasma sheath similar to that observed for PF discharges. The current and voltage waveforms are the same as those registered for the conventional PF shots. A typical pinch column is formed during the compression phase. During the run-down phase the plasma sheath velocity amounts to (0.8-2.5)*10/sup 7/ cm/s. The neutron yield is proportional to the velocity just as for the static pressure mode. The highest neutron yield has been obtained with a high pressure (up to 40 atm) inside the valve plenum. The correlation function maximum can be shifted by changing the gas-puffing conditions. Thus the modification of an initial gas density profile has an effect on the generation of electron beams interacting with a plasma as well as on the neutron production mechanism.<>