Title :
Cryocooler assisted cryostat for a 4 T split-coil NbTi magnet
Author :
Petrillo, E. ; Ariante, M. ; Mariani, M. ; Masullo, G. ; Matrone, A. ; Quarantiello, R.
Author_Institution :
Ansaldo-CRIS, Napoli, Italy
fDate :
3/1/2002 12:00:00 AM
Abstract :
A cryocooler assisted cryostat for a 4 T split-coil NbTi magnet operated in liquid helium bath is under development at the ANSALDO-CRIS. A two stage GM cryocooler (1st stage 15 W @ 45 K, 2nd stage 5 W @ 15 K) is used for the cooling of two radiation shields at temperatures less than 45 K and 15 K respectively. For magnet charge, a couple of 100 A vapor cooled HTS current leads, based on Bi-2223/AgAu tapes, operates between the 1st stage of cryocooler and the helium bath. AlN plates have been used to obtain a good thermal contact electrically insulated between HTS lead and cryocooler. The developed configuration allows to eliminate liquid nitrogen cooled radiation shields and to minimize static liquid helium consumption. Calculated and measured system performances are compared.
Keywords :
cooling; cryostats; heat losses; niobium alloys; superconducting magnets; thermal insulation; titanium alloys; 15 K; 4 T; 45 K; HTSC current leads; Joule heating; NbTi; cryocooler assisted cryostat; heat generation; liquid helium bath; radiation shields; resistive current leads; split-coil magnet; system performances; thermal contact; thermal losses; total losses; two stage GM cryocooler; Contacts; Cooling; Couplings; Dielectrics and electrical insulation; Helium; High temperature superconductors; Magnetic shielding; Niobium compounds; Nitrogen; Titanium compounds;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2002.1018653
