| Irfu-10-381
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| Cryogenic characteristics of the R3B-GLAD magnet |
| Lottin J.P.*, Eppelé D.**, Gastineau B.*, Graffin P.**, Mayri C.*, Massinger M.**, Queinec Y.**, Pes C.* |
| The R3B-GLAD magnet is a large acceptance superconducting dipole that will allow experiments with radioactive beams on FAIR facility at GSI Darmstadt, Germany. The cold mass of 25 tons is made from a set of 2 main coils and 2 lateral pairs of coils in their aluminum casings and covers, fixed on three cryogenic supports. The indirect cooling of the coils with copper braids attached on the aluminum casings has been chosen to cope with the differential thermal expansion. The thermosiphon circuit with a two-phase helium flow, which maintains the cold mass at 4.4 K with a small temperature margin can operate with a variable heat load exceeding 15 W. Its originality is the gentle slope of the heat exchanger tubes glued on the cold mass and its compact geometry, where the phase separator is placed above the tubes in the main vacuum chamber, while the current leads connections and the valves for fluid distribution are in the lateral satellite. This paper presents the cryogenic design of the magnet in the cryostat, and gives its thermal characteristics. |
