液氦温区脉管制冷机的频率特性

着重研究了操作频率对液氦温区脉管制冷机性能的影响，在实验和分析的基础上，明确了制冷温度、制冷量、制冷效率与工作效率之间的关系，并与4K G－M制冷机的情况进行比较，得出了一些有益的结论。通过频率优化，脉管制冷性能得以较大提高。在初步试验中，分别在1．2Hz和1．1Hz获得了30W@70K,500mW@4.2K以及20W@65K,590mW@4.2K的制冷量。同时还给出了脉管制冷湿度稳定性的测试结果。试验结果表明，研制的脉管制冷机温度波动均小于同类商品型4K GM制冷机及脉管制冷机。

FREQUENCY CHARACTERISTICS OF A 4 K PULSE TUBE COOLER

Frequency effects on the performance of a 4 K pulse tube cooler(PTC)have been extensively explored recently The cooling powers at the two stages are much improved by frequency optimization In the preliminary experiments cooling powers of 30 W@70 K,500mW@4 2 K at 1 2 Hz and 20 W@65 K,590 mW@4 2 K at 1 1 Hz are obtained,respectively The mechanism of frequency effect on the 4 K PTC is revealed Some conclusions are drawn,which are very helpful for further developments of not only pulse tube refrigerator but also other G M type cryocoolers Tests of temperature stability are also performed The temperature fluctuation at both stages with some cooling powers is much smaller than those of commercial products for 4 K GM coolers and 4 K PTCs