Radioisotope powered light sources

Radioisotopes have been used for a number of years to excite phosphors to produce visible light. The advent of the nuclear age, however, made possible the preparation of radionuclides in larger quantities at relatively low prices, and with radiation properties that greatly expanded the potential applications for such lights. Current energy conservation needs and inflation leading to even higher costs for maintenance and capital equipment has provided the incentive for development of illuminators for air field markers using both byproduct krypton-85 and processed tritium. Background and current status of these developments are discussed