High speed and spectroscopic investigation of 300 kV pulsed vacuum spark in centimeter gap

The spark stage of pulsed vacuum discharge with initial amplitude 300 kV in point cathode-plane anode gap was investigated by means of high speed imaging with streak-camera in visible and UV region. Also the optical spectra of the cathode and anode plasma in visible and air UV region were taken. Anode and cathode were made of molybdenum and the gap distance was 6 mm. Discharge duration was 200 - 300 ns and the spark current reached 2-3 kA at the end of the discharge. Anode spot appeared at the end of the discharge when the energy delivered to the anode reaches about 10 J. In the anode plasma spectrum mainly the neutral atom spectral lines present, meanwhile in the cathode spot spectrum the strong lines of singly and doubly ionized atom lines are presented.