Measurement of the 150-nm brightness temperature of a high-current discharge in nitrogen

A photoelectric method was used to determine the brightness temperature (in the region of 150 nm) of a high-current discharge in nitrogen at a pressure of 1 atm. A standard source of light, utilizing pulsed discharges in an evacuated capillary and characterized by a brightness temperature of 37000°K, was used for calibration purposes. When the current was ~250 kA and the rise time was ~5 μsec, the discharge in nitrogen behaved as a blackbody with a temperature of 36000°K.