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Cold Cathode

Cold cathode instead of a hot filament.

Cold Cathode

Today’s X-ray tubes are based on the same principle; a thin tungsten wire called filament is heated, like in old type light bulbs, until it emits electrons. These electrons are accelerated by applying a high voltage across the cathode – anode of the tube. When the emitted electrons hit the anode, X-rays are produced.

Using a cold cathode eliminates some of the problems and limitations of using a tungsten filament to emit electrons. Most of the energy supplied to the filament generates heat and the filament has a warm-up and stabilization phase before it reaches the desired state. In addition, a worn-out filament is a common cause of tube failures.

Using a nanomaterial structure, Luxbright’s cold cathode tubes emit electrons from the nanomaterial with much better control, efficiency, and precision compared to using a filament. Field emission is used to generate electrons, which does not require heat, unlike a filament that releases electrons through thermionic emission. Energy losses are reduced to a minimum and electron emission can be switched on and off, instantly. In addition, the inherent quality issues with filament material and performance are eliminated.

Cold cathode sources will enhance future X-ray systems: