A stable, high-intensity resonance lamp operated by a 2450 Mc/sec microwave power source has been developed which is of sufficient intensity and stability to be useful for the kinetic study of photochemical reactions. This light source has maintained a constant output (approximately 2 × 1017 quanta/sec for krypton) for times ranging from 80 h to 120 h. The optimum pressure of krypton in the lamp is 0.28 torr.
J. J. Sparapany, "A Stable, High-Intensity Vacuum Ultraviolet Source," Appl. Opt. 4, 303-305 (1965)