Booster Cryostat for Temperatures down to 0.74°K

Abstract

The cryostat produces temperatures down to 0.74°K by pumping on a liquid helium bath with a large diffusion pump. A shielding pot containing liquid helium at 2°K reduces heat influxes to the main bath and plays a very important role in reducing the pressure drop arising from viscous flow of the gas up the helium Dewar. The low temperature region is visible and the experimental apparatus is easily accessible merely by removing two glass Dewars.