Performance of a superconducting solenoid magnet for BELLE detector in KEKB B-factory

A large superconducting solenoid magnet with an inner warm bore of 3.4 m in diameter and 4.1 m in length has been developed for the BELLE particle detector, which is installed in the KEKB colliding beam ring. The solenoid was installed into the BELLE iron structure. The solenoid was cooled down by using a computer-controlled cooling system and was successfully energized up to a design field of 1.5 T with no training quenches.