Abstract:
This invention improves the stability and control of high-pressure glow discharges by means of a microhllow cathode discharge. The microhollow cathode discharge, which is sustained between two closely spaced electrodes with an opening formed in the electrodes, serves as a plasma cathode for the high-pressure glow. Small variations in the microhollow cathode discharge voltage generate large variations in the microhollow cathode discharge current and consequently in the glow discharge current. In this mode of operation the electrical characteristic of this invention resembles that of a vacuum triode. Using the microhollow cathode discharge as a plasma cathode, stable, dc discharges in argon up to atmospheric pressures can be generated. Additionally, parallel operation of these discharges allows for the generation of large volume plasmas at high gas pressure through superposition of individual glow discharges. Thus, this invention allows simultaneous generation of relatively high electron densities at relatively low temperatures with stable, direct current, homogenous glow discharge plasma at relatively high pressure.
Abstract:
There is provided a preform for a fluorescent lamp comprising a bulb and a stem provided with a filament and a discharge electrode and a fluorescent lamp prepared by the preform without an exhaust pipe for use as an indicating lamp, the fluorescent lamp being sealed after exhausting inside air and charging inert gas and mercury through an appropriate space formed between the bulb and the stem inserted into the bulb. Thus, even when liquefied mercury is present in the discharge chamber, it receives a large amount of heat from the filament applied voltage and is easily and quickly evaporated, whereby the characteristics of the lamp become stable quickly after turning on the lamp.
Abstract:
A glow discharge starter having an hermetically sealed envelope containing an ionizable medium, a bimetallic electrode including a first bimetallic element having a curved portion and a free end, and a counter electrode. A first discharge gap having a predetermined spacing is formed between the free end of the first bimetallic element and the counter electrode. The starter includes a second bimetallic element having an end secured to the counter electrode. A portion of the second bimetallic element is positioned adjacent the curved portion of the first bimetallic element such that a second discharge gap having a predetermined spacing is formed therebetween. In the event that the starter encounters a dc current of the wrong polarity, a portion of the second bimetallic element contacts the first bimetallic element so as to extinguish the arc discharge and prevent electrode damage.
Abstract:
A negative glow discharge lamp having improved efficacy enabled by reducing the anode work function by the introduction of a metal-based gas into the lamp envelope for absorption on the anode. The metal-based gas is preferably cesium but may also, for example, be sodium.