Spatio-temporal distributions of copper vapor particles in a vacuum arc discharge plasma

Spatio-temporal behavior of copper (Cu) particles emitted from the electrode designed as an imitation of a vacuum circuit breaker (VCB) was observed to investigate the breaking characteristic of the VCB using laser induced fluorescence (LIF) technique. The use of a Doppler shift of the LIF signal with fluorescence light of 510.55 nm (Cu* 4/sup 2/P/sub 3/2/-4/sup 2/D/sub 5/2/) allowed us to perform the measurements of the diffusion velocity of Cu particle emitted from the electrode during the vacuum arc discharge. The results showed that the Cu particles were distributed between electrodes even after the discharge finished, and its diffusion velocity in the direction of the cathode from the anode was about 2.6/spl times/10/sup 3/ m/s.