Measurement of the mass density evolution of wire explosion using X-ray backlight

The evolution of single-wire and dual-wire Z-pinch of 8μm-W were investigated by X-ray backlighting using an X-pinch X-ray source. The experiments were carried out on the pulsed power generator PPG-I (400kA/500kV/100ns) which was designed and constructed by Department of Electrical Engineering of Tsinghua University. In order to scale the mass density distributions at different explosion time, a mass step wedge including eight tungsten layers was fabricated and inserted between the object Z-pinch and the X-ray film. By a large number of imaging experiments, the physical images of coronal plasma formation and inter-wire plasma merging were obtained. Based on the x-ray photos of 8μm-W and mass step wedge, the mass density distributions at different explosion time were drawn, and the conductance curve of time-dependence of 8μm-W was also calculated using waveform of voltage and current.