GSI SC Dipole Magnet Coil, tested Fairly Good

The first experimental superconducting dipole coil for FAIR (Facility for Antiproton and Ion Research), the project from Gesellschaft fur Schwerionenforschung mbH (GSI), is tested via electric charges and in cryogenic condition, proved to be fairly satisfactory for FAIR, which has a total of twenty four coils.

This dipole superconducting magnet is composed of coils, coil case, thermal shielding, cryostat, supports and current leader, all of which are designed, fabricated and tested at ASIPP. Although our engineers don’t have experience in designing and fabricating such magnet, they have cracked every hard engineering and technical nut.

 To meet the demanding requirement of the ＜1×10 -4 T magnetic field, our engineers adopted double solidification with Vacuum Pressure Impregnation(VPI) technique. A vacuum room was employed in vacuum sealing to avoid welding stress and deformation in order to achieve the dimension and position precision of the coil case. Vertical bend and enormous silver brazing were applied in the process of enwinding copper pipes around the inner and outer surface of thermal-shielding. By quality and effectual clamps and fixtures as well as high grade argon-arc vacuum sealing welding, the cryostat was manufactured and assembled in a large-size sheet metal cryogenic vacuum vessel to shun stress and deformation.

The task of the FAIR experimental dipole coil commenced in January 2006, its detailed manufacture design and high-demanding fabrication is undertaken by Juneng Company, a spin-off company of the institute workshop. (Li Bo reports)