A comparative study of the excitation conditions in the plasma and the electrical parameters of a d.c. arc when using power-stabilized,current-stabilized and manually controlled d.c. sources

The abilities of three d.c. arc sources—a manually controlled source, a constant current source and a constant power source—to control variations in arc temperature, electron pressure and anode temperature were compared, and the dependency of these factors on the electrical parameters was investigated. It was shown that with well buffered samples there is little advantage to begained in using any one of the three sources. With poorly buffered samples, however, the constant power source showed greater control over the variations in arc temperature, electron pressure and anode temperature. It was also shown that the only electrical. parameter which could be used to obtain an estimate of the arc temperature is the arc power.