The anode surface temperature of CuCr contacts at the limit of current interruption

This paper estimates anode surface temperature at the current interruption limit by measuring the melting time of a contact material after current interruption and simulating the anode surface temperature. As a result, the minimum anode surface temperature of CuCr(50/50) contact material was about 1750 K. We also calculated the metal vapor density between electrodes with a simplified model. The calculation results showed that the critical vapor density was about 3/spl times/10/sup 20/ atoms/m/sup 3/. This vapor density is equivalent to the averaged pressure of 8 Pa, which is close to the value of the Paschen minimum.