Effect of pressure on the axial phase dynamics of a small plasma focus

Summary form only given, as follows. A measurement of argon plasma dynamics has been made in correlation with X-rays produced by a small 3 kJ plasma focus. The speed of the plasma sheath was measured using a magnetic probe X-rays produced by the focussing plasma was measured using a four channels PIN diode spectrometer. The spectral contents of the X-ray and the plasma electron temperature were obtained by the ratio method. For discharge at 0.5 and 3 mbar, the speed of the current sheath was measured. The electron temperatures were deduced to be 1.2 keV at high pressure and more than 5 keV at low pressure. Results show that when the plasma focus is operating at low pressure the plasma is contaminated with copper impurity. A simulation of the axial dynamics of the plasma focus was also carried out and the results are compared with those obtained experimentally.