Miniature 10-150 mW Linde-Hampson cooler with glass-tube heat exchanger operating with nitrogen

Two demonstrator versions of a small Linde-Hampson cooler with glass tube heat exchanger are presented. The fabrication of these coolers are described and exptl. results are presented and discussed. One cooler with a length of 270 mm and an outer diam. of 0.67 mm has a cooling power of 60 mW at 88 K with a mass flow of 7.3 * 10-6 kg/s (0.35 ln/min1) nitrogen gas. The lowest temp. measured is 82 K at a mass flow of 4.2 * 10-6 kg/s. The other shorter cooler has a length of 105 mm and the same outer diam. It could also reach 82 K with a flow of about 2 * 10-6 kg/s. In both cases nitrogen gas was supplied at a pressure of 10 MPa.