A simple and versatile liquid nitrogen cooled cryostat on a differentially pumped rotary feedthrough

We report here a simple and improved design which extends the versatility of a liquid nitrogen cryostat on a differentially pumped rotary feedthroug h. The novel modifications are: 1) the cryostat is isolated from the inne r surface of the rotary feedthrough; 2) additional feedthrough ports are incorporated that are not in contact with the liquid nitrogen cryostat; 3) a liquid nitrogen reservoir is employed that is thermally isolated throug h the use of a vacuum jacket. (AIP)