A radiation source developed for broad band optical absorption spectroscopy measurements

In order to investigate the post-arc period and the hot gas regions surrounding the electrical arc in circuit breakers, a broad band radiation source has been developed to perform absorption spectroscopy measurements. The source consists of a Z-pinch electrical discharge in which the high temperature and the high density argon plasma obtained at maximum compression produces an extremely intense continuous radiation pulse of about 2 μs duration. The radiation spectrum has been characterized both temporally and spectrally in order to determine the best operating conditions to produce an intense and continuous radiation spectrum. Absorption tests have been performed on the hot gas region of a low voltage rail gap circuit breaker. Absorption of copper atom resonance lines (Cu I 324.75 and Cu I 327.40 nm) is used to determine the copper atom density in the rear of the arc. In addition, absorption of the C 2 molecule Swan bands, (0,0) and (1,1), is used to determine roughly the concentration of C 2 and also the kinetic temperature of the hot gas.