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:
- Lighter, more energy-efficient X-ray equipment - even battery-powered - is one example with applications in ambulances or for customs when inspecting goods in trucks or on a ferry deck.
- Lower dose thanks to improved pulsed radiation is another example.