The present invention provides a bulb (100, 110, 120, 130, 140, 140) an excitation chamber (200, 210, 220, 230, 230) a ferrite core (300, 310, 310), a spool (400, 410); an assembly or subassembly of such components, and a lamp (100, 1100, 1200, 1300, 1400, 1500, 1600, 1600, 1600, 1700, 1800) for producing electromagnetic radiation, such as in the light spectrum, UV or IR.