Enhanced and reproducible X-ray emission in a low-energy plasma focus

Abstract

The effect of pre-ionization by a shunt resistor on X-ray emission performance from a low-energy (2.7 kJ) plasma focus is investigated by employing time-resolved and time- integrated detectors. Different shunt resistors are employed and 71 MΩ is found the most appropriate in this experiment. It is estimated that with pre-ionization 49.56 J of energy is radiated as X-rays, out of which 21.5 J is in the form of Cu-Kα lines in 4π-geometry. The pre-ionization enhances the X-ray yield, broadens the working gas pressure range and improves the shot-to-shot reproducibility of the system. The pinhole images of X-ray–emitting zones indicate that the dominant X-ray emission is from the anode tip, although the emission from hot spots along the pinch axis also contributes.