Large high current density superconducting solenoid for the time projection chamber experiment

One of the experiments for the PEP storage rings at the Stanford Linear Accelerator Center uses a superconducting magnet to provide the magnetic field for the Time Projection Chamber detector. This magnet has an inside diameter of 2.04 m and a gap of 3.26 m. The magnet central induction is 1.5 T. This magnetic induction is supplied by a thin high current density superconducting coil which is less than 0.4 radiation lengths thick. The magnet stored energy will be 10.9 MJ; the coil superconductor matrix current density will be about 7.0 x 108 Am-2. The TPC magnet uses a two-phase forced flow tubular cooling system which combines many of the advantages of single-phase supercritical helium cooling with those of boiling helium bath cooling