Balance line for HERA proton main ring

A balance line was installed in the HERA superconducting main ring. The balance, connected to the dump resistors during a fast discharge, separates the main ring into nine independent loops. Under fault conditions, the voltages to ground of the superconductor can rise four times higher than in the symmetric case. The balance line of HERA can limit the overvoltage to a factor of two under fault conditions, including full sector quenches, nonoperating breakers, switching time jitter of the breakers, and traveling waves along the string. The balance line allows a unified operation for a fast discharge and is tolerant of faults. This simplified the protection of large superconducting magnet strings