Performance of an internally cooled superconducting solenoid

A superconducting magnet constructed of an internally cooled solenoid was produced and tested. Particular emphasis was placed on measurement of the stability margins of the magnet. Test results showed that: (1) this magnet reached short sample critical current limit with no training; (2) no degradation due to strand motion in fields was apparent; (3) it can be charged and discharged to high current densities and high fields at a fast rate; (4) it has reasonable stability margin up to 90% of the critical current; (5) stability measurements verify the scaling relationship for a limiting current below which there is single valued high stability margin; (6) it is not really necessary to have bulk helium flow to ensure high stability; and (7) very high pulse field changes can be accomodated as long as the energy deposition is within its stability margin.