Helium Composite Regenerator

第二阶段计划的目标是制造和测试新型低温复合材料，设计用于在低于10 K的闭式循环制冷机中作为蓄热器。该材料是氦自加载成金属扩展表面结构的复合材料，其弥散形式适合于蓄热器的热流通量和频率要求。3 ~ 6 K时的高有效热容量来源于亚临界氦的汽化冷凝潜热，10 K以下的高热容量来源于加压氦的显热容量。蓄热器的高各向异性导热系数来源于金属成分的几何形状。高热容量和高径向导热系数的结合允许快速热渗透和高再生效率。在液氦温度下，使用不涉及焦耳-汤姆逊气体节流阶段的闭式循环制冷机，有可能获得显著的制冷功率。

The object of this Phase II program is to fabricate and test novel cryogenic composites designed for use as regenerators in closed-cycle cryocoolers operating below 10 K. The material is a composite of helium self-loaded into a metallic extended surface structure whose dispersion form is suitable for the thermal flux and frequency requirements of regenerators. High effective heat capacity from 3 - 6 K derives from the latent heat of vaporization and condensation of subcritical helium, and high heat capacity below 10 K derives from the sensible heat capacity of pressurized helium. High, anisotropic thermal conductivity in the regenerator derives from the geometric form of the metallic component. The combination of high heat capacity and high radial thermal conductivity allows for rapid thermal penetration and high regenerator effectiveness. The potential exists to achieve significant refrigeration power at liquid helium temperatures with a closed-cycle cryocooler not involving a Joule-Thomson gas- Throttling stage.