Soft x-ray emission form a small plasma focus operated in deuterium

Using composite anodes in a 3 kJ plasma focus device operated in deuterium, peak axial sheath velocities up to 15 cm mu s(-1) are achieved. The temporal characteristics of the soft x-ray emission are investigated by means of filtered PIN diodes. Correlations with hard-x-ray and neutron emission as well as with electrical parameters of the discharge are performed. Two distinct operation regimes are identified regardless of the shape of the anode. Various scaling laws of the soft x-ray production are investigated. We propose a new scaling law for the soft x-ray yield.