At one end of the tube is the hot cathode heated by a filament which produces electrons.
12.
Hot cathode gauges are accurate from 10 & minus; 3 Torr to 10 & minus; 10 Torr.
13.
Hot cathodes typically achieve much higher power density than cold cathodes, emitting significantly more electrons from the same surface area.
14.
CaB 6 is highly conductive, has low work function, and thus can be used as a hot cathode material.
15.
The first true electronic vacuum tubes, invented in 1904, used this hot cathode technique, and they superseded Crookes tubes.
16.
Because cold cathode lamps have no thermionic emission coating to wear out they can have much longer lives than hot cathode tubes.
17.
All triodes have a hot cathode electrode heated by a grid consisting of a screen of wires between them to control the current.
18.
The EB furnaces use a hot cathode for production of electrons and high voltage for accelerating them towards the target to be melted.
19.
Lanthanum hexaboride ( LaB 6 ) and cerium hexaboride ( CeB 6 ) are used as coating of some high-current hot cathodes.
20.
Instead, they use a more reliable and controllable source of electrons, a heated filament or hot cathode which releases electrons by thermionic emission.
