Experimental Investigation of Compact 2 K GM Cryocoolers

On the basis of a conventional 4K Gifford-McMahon (GM) cryocooler, we developed a new 2 K GM crycooler, which can provide considerable cooling capacity and yet being highly compact in physical size. A series of experiments were conductedto confirm and show the cooling characteristic and cooling capability of this new cryocooler. Under no-load condition, the lowest temperature reached about 2.1K on the secondstageand the temperature oscillation displacement was less than ±20mK. Even under a thermal-load of 1 W/20 mW, temperature reached 44.4 K on the first stage and 2.23 K on the second stage. Detailed cooling load-map and cool-down curve will also be introduced in this paper.