Abstract:
An enclosed vessel containing one or more main anodes, one or more auxiliary anodes, a cathode, and means for maintaining a low pressure in the tube comprises a liquid-metal arc switching device. The cathode is fed with a metal which is liquid at convenient temperatures, so that limited quantities of the metal are present and available on the cathode for arcing. The interior of the vessel is maintained at a low background pressure so that during nonconduction, vacuum space insulation is provided between the anodes and the cathode. Arc initiation is accomplished by any convenient initiator, and the arc runs upon the small amount of liquid metal fed at an appropriate rate to the cathode. Arc extinction is accomplished by causing current to flow from the cathode to the auxiliary anodes at rates substantially higher than the main anode current. This causes consumption of the liquid metal at a higher rate than the liquid-metal feed rate, with consequent arc extinction by cathode starvation.
Abstract:
Orientation independent ignitron 10 has a cooled cathode 28 which carries thin mercury film 58 which is held in place by surface tension forces so that it is independent of orientation. Ignitor 48 starts conduction which continues until mercury exhaustion or shut off by an external circuit. During nonconductive portions of the duty cycle, the mercury recondenses on the cooled cathode 30.
Abstract:
The liquid metal cathode is employed as a cathodic electron source in arc discharges. A small liquid metal pool serves as the arcing material, and when it is kept small, improved electron-toatom emission ratios are obtained, as well as gravity independence. However, when such a small pool is employed, feed to the pool must be free of feed rate perturbations. Otherwise, an instability in the level of the mercury in the pool results. The present invention obtains feed rate stability by providing a feed passage with a diameter which is everywhere larger than that of the feed channel which finally discharges to the pool. Feed flow impedance is provided by an elongated capillary feed channel.