Poh Foong, L: Spectral Measurements Of a Vacuum Spark X-Ray

This project reports on the studies of the spectra and X-ray dosages of the copper, aluminium and carbon plasmas produced by an electron beam initiated hollow cathode vacuum spark. Various diagnostic techniques are employed simultaneously for the studies, which consist of a magnetic pick up coil, a BPX65 PIN diode and PIN diodes and a high resolution X-ray spectrometer. The results obtained are analyzed to give information on the discharge characteristics, the spectra of the anode materials. The K lines and continuum background spectra are observed from the pre-breakdown electron beam anode interaction. For discharges where hot spot formation is observed, the spectra observed also exhibit similar feature of continuum and K lines, but with amplitude of the K line very much enhanced. This indicates that the plasma emission is dominated by K line radiation. The electron temperature of such a plasma is estimated from the peak of the continuum to be around 3 keV, which according to the CE model, corresponds to 70 % of Cu27+ species. Thus the strong K lines are present in the measured spectrum. The X-ray plasma source of the aluminium anode and carbon anode are isotropic.