Study on the proportions of charged particles absorbed by post-arc anode in the post-arc phase of a vacuum circuit breaker

The post-arc dielectric recovery process has a decisive effect on the current interruption in the vacuum circuit breakers. A large amount of plasma emitted by the cathode spots in the arcing phase still exists in the inter-contact region at the moment of current zero. Then an ion sheath forms in front of post-arc cathode and develops to the post-arc anode. The charged particles are absorbed by the post-arc cathode and anode, which forms the post-arc current. Most of the electrons in the gap enter the post-arc anode during the post-arc sheath expansion process. However, some ions still enter the post-arc anode during this process as well. The residual charge obtained from the integration of post-arc current in experiment, should be the net electron absorbed by the post-arc anode. Then the electron density can be estimated with the proportion of charged particles absorbed by post-arc anode. This could also be a relative easy way to estimate the residual plasma density from measurement. However, there are few discussions about the charged particles absorbed by the post-arc anode during the post-arc sheath expansion process. In this paper, we study the proportion of charged particles absorbed by post-arc anode with different factors, e.g. residual plasma temperature, and the contact gap. From the simulations we can see that the proportions show small variation with these two factors.