液氦温区双小孔型二级脉管制冷机实验研究

Experimental study of double\|orifice pulse tube refrigerator reached liquid helium temperatures

介绍了自行研制的二级双小孔型脉管制冷机的基本结构，着重分析了第二小孔、结构参数对制冷机性能的影响，指出了进一步改进的方向． 实验表明，采用双小孔结构的二级脉管制冷机第一、第二级最低制冷温度分别达到４６ Ｋ 和３．０ Ｋ．

Experiments were performed on a self\|made double\|orifice two\|stage pulse tube refrigerator to study the effects of the double\|orifice on the performance of the refrigerator and to determine the minimum refrigerative temperature. The experimental results comparing the double\|orifice version with the double\|inlet version verified that the former could reach a lower temperature than the latter. A lowest temperature of 3.0 K was obtained with the double\|orifice version in the present study. It appears that the second orifice enhances the phase shifting effect of the same stage orifice and improves the temperature distribution of the pulse tube.