Tests of a GM Cryocooler and high Tc leads for use on the ALS superbend magnets
A 1.5 W (at the second stage) Gifford McMahon (GM) cryocooler was selected for cooling the superconducting SuperBend dipoles for the Advanced Light Source (ALS) at Berkeley. A GM cryocooler is a reasonable choice if conduction cooled leads are used to provide current to the superconducting magnet. The expected parasitic heat leaks are expected to range from 0.1 to 0.5 W at 4.2 K depending on the temperature of the shield and the cold mass support intercepts. Heat flow to 4 K down the SuperBend 350 A high Tc superconducting leads is expected to vary from 0.11 to 0.35 W depending on the intercept temperature and the current in the leads. The high Tc leads are designed to carry 350 A without significant resistive heating when the upper end of the lead is at 80 K. The 1.5 W cryocooler is expected to provide 45 to 50 W of refrigeration at the first stage at 50 K. The parasitic beat load into the first stage of the cryocooler will be about 8 W. The heat flow from 300 K down the upper copper leads is expected to be around 30 W. The cryocooler and high Tc lead test will measure the penormance of the cryocooler and the high Tc leads. The heat leak down the cryocooler, when it is not operating, is also of interest.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Engineering Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 1011497
- Report Number(s):
- LBNL-43573; TRN: US201109%%462
- Resource Relation:
- Conference: Cryogenic Engineering Conference and International Cryogenic Materials Conference, Montreal, Quebec, Canada, July 12-16, 1999
- Country of Publication:
- United States
- Language:
- English
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