Abstract
Pressurized superfluid helium (He IIp) was successfully produced in a Claudet type cryostat made from G-FRP without a nitrogen temperature shield.
No super-leak occurred and the efficiency of refrigeration has remained constant over more than 20 cyclings between room and He IIp temperatures. The plastic dewar was prepared to investigate hybrid cooling of an A. C. or pulsive superconducting magnet wound from a hollow type conductor; the inside of which is cooled by saturated superfluid helium (He IIs) and the outside is simultaneously cooled by He IIp. The He IIs dose not circulate.
