Theoretical and experimental investigation of the spontaneous fluctuations of the infrared radiation of a high-current high-pressure argon discharge

The plasma of a stationary argon arc discharge at high pressure was used as a radiation source. By measuring and calculating the continuous photon radiation, it is possible to determine the temperature distribution in the plasma. Owing to the high temperatures as well as the sufficient optical thickness in the infrared spectral range, determination of the fluctuation factors is made possible. The agreement between measured and calculated factors is good. Instabilities in the plasma have been considered and eliminated in the experimental procedure.