Electrodeless low pressure lamp with multiple ferrite cores and coils

摘要

An electrodeless low pressure discharge lamp comprises an envelope made from a straight tube and a reentry cavity sealed to one of tube's ends. The cavity has several hollow ferrite cores separated from each other with a few mm distance. Each ferrite core has an induction coil of few turns wound around the core. Each cavity has a cooling copper tube or rod located inside the ferrite core that removes heat from the cores and dumps the heat into a heat sink welded to the cooling tube/rod thereby keep the temperature of the ferrite cores below their Curie point. Each induction coil is electrically connected to the matching network while all matching networks are connected in parallel to the high frequency power source (driver). Inductively coupled plasmas generated in the envelope by several core/coil assemblies produce axially uniform UV and visible radiation.