Current Leads Test for FECR Cryostat

To fulfill the normal operational requirements of the fourth generation electron cyclotron resonance ion source (FECR) superconducting magnet, a cryostat in the form of liquid helium immersion was designed based on several Giffod McMahon cryocoolers. Considering the substantial number of current leads (a total of 9) and the high current value (with the maximum current of 709 A) of the superconducting magnet, a dedicated current lead test platform was designed and constructed to ensure operational stability and thermal management of the cryostat. This platform was utilized to conduct comprehensive tests on the high temperature superconductivity (HTS) leads and room temperature copper leads intended for use in the cryostat, including quantitative evaluation of conductive heating load and Joule heating load under operational conditions. The test results demonstrate that the designed leads can meet the normal working requirements of the FECR cryostat, achieving a maximum current capacity of 720 A with heat load of 28.88 W per copper lead and 0.12 W per HTS lead, respectively.