kylmäkatodisähköpurkaus

kylmäkatodisähköpurkaus, often translated as cold cathode discharge, refers to an electrical discharge that occurs at low gas pressures and temperatures where the cathode is not heated to facilitate electron emission. Unlike hot cathode discharges which rely on thermionic emission, cold cathode discharges utilize other mechanisms to initiate and sustain the flow of current.

These mechanisms can include field emission, where electrons are pulled from the cathode surface by a strong electric field, or secondary electron emission, where ions striking the cathode knock out electrons. The gas in the discharge tube is typically ionized by the initial stream of electrons, creating a plasma. This plasma then sustains the discharge.

Common examples of devices that utilize cold cathode discharge include neon signs, fluorescent lamps (though these also involve a hot cathode in modern designs), and various types of gas discharge tubes. These discharges are often characterized by specific colors depending on the type of gas used and the operating voltage. The low operating temperatures and relatively simple construction make cold cathode discharges suitable for a variety of applications where high temperatures are undesirable or impractical.