Test of BESIII Detector Magnet

The Beijing Spectrometer III (BESIII) detector magnet running in Beijing electron positron collider reached its nominal current successfully in 2008. The 3.39 m diameter, 3.91 m long superconducting solenoid magnet (SSM) provides a 1 Tesla central magnetic field. It was inner wound with aluminum stabilized NbTi/Cu cable and conduction—cooled with forced flow of two phase helium circulating in a tracing tube. A thermal shield was conduction—cooled with liquid nitrogen in the cryostat. This paper reports the experience of the test of the BESIII detector magnet.