Novel techniques for the thermal management of space-based, high-power microwave tubes

This work is based in part on a study (M.F. Rose et al., 1989) by the authors to determine the applicability of several concepts to the cooling of high-power linear microwave tubes operating in space under a variety of conditions. The authors focus on: direct radiation to space, beam exit to space, thermal storage, secondary coolant loops/heat pipes and the use of supercritical hydrogen as a coolant with subsequent ejection to space. Each of these techniques is evaluated within the framework of a neutral particle beam weapons system or other limited duty cycle device which might lay dormant for long periods of time, come to life, and function reliably for a specified time. System impact for each technique is estimated in terms of impact on weight, volume, spacecraft interaction, and ease of implementation