A superconducting solenoid for heavy ion beam focusing

A 6 T superconducting solenoid has been constructed to focus heavy ion beams on the production target of radio isotope beams. The design field on axis is 6.2 T with an average current density of 9,600 A/cm². The overall coil length is 1.1 meter, and the coil is divided into three equal-length sections to ease winding and to reduce IR drop through diode connection. A main feature of the system is that the solenoid is conductively cooled by a cryocooler directly attached onto the center coil without liquid helium involved. The solenoid was successfully trained to 6.2 T, and its optical properties were tested in the beamline at RIKEN. The design features and the test results are presented