Electrodes

Electrodes in UV-C germicidal lamps are critical components that facilitate the electrical discharge process within the lamp's gas-filled tube. They are typically made from specialized metals and alloys that can withstand high temperatures and electrical stresses. When voltage is applied, electrons are emitted from the cathode electrode, ionizing the gas mixture (usually mercury vapor and inert gases) to produce UV-C radiation at 254 nm wavelength. The electrodes must maintain stable arc discharge while resisting sputtering, erosion, and thermal degradation over thousands of operating hours.

Electrodes operate on thermionic emission and field emission principles. The cathode electrode is heated (either directly or indirectly) to release electrons into the gas-filled chamber. These electrons collide with gas atoms, creating plasma through ionization. The anode collects electrons to complete the circuit. This sustained electrical discharge excites mercury atoms, which then emit UV-C photons when returning to ground state. Electrode design ensures consistent electron emission and stable discharge throughout the lamp's lifespan.