Comparative studies of X-ray emission from a plasma focus with different metal inserts at the anode tip

X-rays emission from a low energy (1.4–5.3 kJ) Mather-type plasma focus device with different (Cu, Mo, W and Pb) inserts at the anode tip is reported. The space and time resolved X-ray emission characteristics are investigated by using a multichannel pindiode spectrometer and a simple pinhole camera with appropriate filters. The variation of total X-ray yield and corresponding efficiency with discharge current, charging voltage and stored energy is investigated. At optimum conditions, the maximum X-ray yield in 4π-geometry is found to be 67.6, 62.4, 64 and 46.5 J/shot with Cu tip, Mo, W and Pb inserted anodes, respectively, and corresponding efficiencies for X-ray generation are 1.5, 1.4, 1.2 and 1.4%. In case of Pb inserted anode X-ray yield deterioration is observed for charging voltages grater than 23 kV. Pinhole images of the X-ray emitting sites reveal that soft X-rays are emitted from focus region, whereas hard X-rays are emanated from anode tip.