Commissioning and operation of the cryostat for 3W1 SC wiggler

A 3W1 superconducting wiggler (SCW) with the pole gap of 68 mm was successfully tested and installed in a BEPC II storage ring in November, 2019. The goal of zero liquid helium consumption was achieved, and the cryogenic system exhibited a 12% residual cooling capacity (approximately 0.69 W @4.2 K). The 3W1-SCW was set to operate at 2.49 T and has been operating for more than seven months. Three instances of magnet quenching occurred during the normal operation. The evaporated helium gas can be recycled to the helium gas recycling system when the pressure in the helium tank is higher than the parameter value (the setpoint of the pressure value is 1.2 bara). The cryogenic system can be recovered within 4 h if sufficient liquid helium is available to inject into the cryostat.

Automated summary

A 3W1 superconducting wiggler (SCW) with a 68 mm pole gap was successfully tested and installed in a BEPC II storage ring in November 2019. The goal of zero liquid helium consumption was achieved, and the cryogenic system exhibited a 12% residual cooling capacity (approximately 0.69 W @4.2 K). The 3W1-SCW was set to operate at 2.49 T and has been in operation for over seven months. Three instances of magnet quenching occurred during normal operation. The evaporated helium gas can be recycled to the helium gas recycling system when the pressure in the helium tank exceeds the parameter value (setpoint pressure value is 1.2 bara). The cryogenic system can be recovered within 4 hours if sufficient liquid helium is available for injection into the cryostat.