Effect of inter-electrode gap on the emission of EUV and x-ray radiation from vacuum spark discharges

Abstract

The emissions of X-ray and Extreme Ultra Violet (EUV) from plasmas produced by vacuum spark discharges are investigated. The vacuum spark plasma emits both continuum and characteristic line radiations that cover a wide range of wavelengths extending from the visible, UV, EUV, soft X-ray and to hard X-ray region. Experiments have been carried out with stainless steel anode. The applied voltages are from 6 kV to 20 kV. The operating pressure for all the experiments carried out is maintained at below 10-4 mbar. In order to have a good soft-X-ray emission (maximized), an optimization of the main experimental parameters (capacitor charging voltage, anode - cathode separation, and trigger pulse amplitude) has been performed. The inter-electrode gap is found to be a dominating parameter to determine the intensity of X-ray and EUV emission from the vacuum spark. The inter-electrode gap distance for high intensity and reproducible X-ray and EUV emission is found to be in the range of 2.6 mm to 6.7 mm. © 2011 American Institute of Physics.