A cryocooler cooled 10 T split pair superconducting magnet for neutron scattering experiment

The authors have designed and constructed a cryocooler cooled 10 T split-pair superconducting magnet for a neutron scattering experiment with a vertical room temperature bore of 51 mm. The magnet, which is directly cooled by two 4 K Gifford-McMahon cryocoolers, consists of (Nb,Ti)/sub 3/Sn coils, NbTi coils, Bi(2223) superconducting bulk current leads and a cryostat. The inner coil with an inner diameter of 78 mm, an outer diameter of 191 mm, a height of 106 mm and a gap of 45 mm is made using (Nb,Ti)/sub 3/Sn conductor and a stainless steel bobbin. The outer coil with an inner diameter of 201 mm, an outer diameter of 300 mm, a height of 104 mm and a gap of 50 mm is made using NbTi conductor and a stainless steel bobbin. The Bi(2223) superconducting bulk current leads are thin walled sintered cylindrical tubes. The outer diameter, height and weight of the system are 600 mm, 760 mm and 280 kg, respectively. The magnet can be cooled down in approximately 52 hours. A continuous operation at 10 T, which is generated by an operating current of 151 A, has been performed. It takes about 15 minutes to excite the magnet up to 10 T.