A CRYOCOOLER FOR SUPERCONDUCTING IMAGING SYSTEMS

可达到液氦温度(4.5K)的闭式循环制冷机 可能会有重要的应用。建议的工作涵盖 基于孔板的四级制冷机的实验论证 脉冲管循环。该设计是基于一个热力学模型的 在第一阶段的努力中开发了制冷机循环。先进的再生器 概念，基于穿孔板的低温是必需的 冷冻机的各个阶段。预测总的COP为5000瓦/瓦 对于制冷机，假设压缩机运行理想。建议数 机器应具有高可靠性，因为它没有活动部件或 低温段中的孔口限制。没有活动部件 也意味着振动和磁性特征很小。这是 对于涉及灵敏磁矩检测器的应用至关重要， 比如鱿鱼磁强计。

Closed cycle cryocoolers that can reach liquid helium temperatures (4.5 K could have important applications. The proposed effort covers the experimental demonstration of a four-stage cryocooler based on the orifice pulse-tube cycle. The design is based on a thermodynamic model of the cryocooler cycle developed in the Phase I effort. An advanced regenerator concept, based on perforated plates is required for the low temperature stages of the cryocooler. An overall COP of 5000 watt/watt is predicted for the cryocooler, assuming ideal compressor operation. The proposed machine should have high reliability since it has no moving parts or orifice restrictions in the cryogenic section. The absence of moving parts also means that the vibration and magnetic signatures are small. This is critical for applications that involve sensitive magnetic moment detectors, such as the SQUID Magnetometer.