When Apollo astronauts stumbled across shimmering orange beads on the moon, they had no idea they were gazing at ancient relics of violent volcanic activity. These glass spheres, tiny yet ...

The present state of knowledge concerning the physical phenomena of high-current interruption with vacuum interrupters (VI) is reviewed. Two arc control methods, application of externally applied ...

The pressure of vacuum switching elements after production is checked normally by Penning or magnetron methods (combined electrical and magnetic field). Vacuum in the range of 10/sup -1/ to 10/sup -4/ ...