RADIATION OF AN EXPLODING WIRE IN VACUUM

Experiments were carried out to study the radiative characteristics of the process of exploding thin (0.3 mm diameter) copper wire 100 mm long in vacuum. The vacuum was considered sufficient for elimination of secondary radiation and absorption effects which accompany the process in a gas medium. The initial voltage on a capacitor bank was 30 kv. The discharge period was 45 micro sec, with a current maximum up to 150 kamp. The experimental setup and the method are described in fair detail. An analysis of a motion picture taken along the wire axis and time-scan spectral photographs taken through a narrow slit parallel to the wire displays, besides the spectral lines of copperr, flashes of continuous spectra. These flashes occur when the luminous regions within the plasma moving away from the electrodes toward each other arrive at the central area of the wire. The nature of these continuous spectra appears to be similar to the continuous spectrum at the beginning of the process. The presence of the absorption spectrum indicates that the temperature corresponding to the luminosity of the continuous spectrum is higher than the electron temperature in the outer layers of the expanding plasma cloud. No absorption spectrum was observed in the red region. Edited machine trans. of mono. Svoistva Gazov pri Vysokikh Temperaturakh; Fizicheskaya Gazodinamika, Termodinamika i Fizika Goreniya (Properties of Gases at High Temperatures; Thermodynamics and Physics of Combustion), Moscow, 1967 p106-109.