Vacuum-Arc Current-Zero Project with Rensselaer Polytechnic Institute (DOE). Appendix A. Interim Report, December 1981

摘要

We have reviewed the vacuum arc literature with particular emphasis on current interruption modeling. We have also set up a current counterpulse circuit, and have made preliminary measurements of plasma conditions prior to and following current zero. Finally, we have initiated analysis of both the Westinghouse data, and the data of other investigators. With respect to the literature review, we have noted the limiting models described as ''static sheath'' and ''ion matrix,'' and the intermediate models developed by Holmes and Yanabu and Childs and Greenwood. We have also noted that previous authors have had to assume an ion speed, following interruption, which is significantly less than the ion speed during steady state arcing. In order to provide additional data on plasma conditions, both prior to and following a current counterpulse, we have measured shield currents and post arc currents using a vacuum interrupter equipped with CLR electrodes. We have confirmed high post arc currents approaching 100A following the interruption of high current arcs of several thousand amperes. Furthermore, the magnitude of both the post arc current, and the total charge collected, increase significantly when the vapor condensation shield is electrically connected to the shield during the post arc period. We have related the charge collected by the electrodes, following interruption, to both the steady state current and the time for that current to reach zero. (ERA citation 11:023372)