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This paper provides the results of a parametric study conducted to assess the relative performance advantages derived from the use of coolants other than water to improve the peformance of the cooled optic or crystal. Cryogenic coolant and liquid gallium were investigated for their effectiveness in temperature and distortion control of an optical surface with an underlying pin post heat exchanger. The heat exchanger configuration remained the same but included changes in entrance and exit areas to accommodate the different coolants studied. The synergism of cooled beam line optics and high energy laser cooled element sees multiple passes by the beam before the beam is outcoupled, and, while smaller amounts of energy are absorbed, the resulting distortion is significant because of the accumulation of wave front distortion from the multiple passes. In the beam line application, large amounts of energy are absorbed but the number of passes is limited to one, and the resulting distortion occurs from the one pass. Thus, the heat exchanger design analysis tools developed for the laser apply to the beam line case without significant modification for the application. The experience base includes anchored analysis techniques that are low-cost and contribute a streamlined design approach toward achieving the desired cooled optical element performance.
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