Construction and testing of a general purpose 50 liter liquid helium cryovessel

The authors have built and are operating a 50 liter liquid helium vessel with an access port for easy insertion of experiments. The vessel is primarily used to test components of superconducting magnet systems, such as cryogenic current leads. The access port is set at a 45 degrees angle and the entire vessel may be tilted 45 degrees in either direction so that current leads may be tested in any orientation from horizontal to vertical. The vessel was designed to be easily disassembled so that experimental apparatus too large for the access port may be mounted directly in the helium can. This way devices 40 cm in diameter may be tested. The heat load of the vessel has been measured under a variety of experimental conditions. A few devices tested so far in the cryovessel are briefly described