DC and pulse operations of 4 MJ pulsed superconducting magnet and its stress analysis

4 MJ pulsed magnet was tested in dc and pulse operating modes, It was successfully charged up to 5940 A ( 4.6 MJ, 6.9 T) at 0.15 T/sec and discharged at 3.5 T/sec without quenching. Strains due to hoop stress were measured and analysed using a spring model. It is pointed out that they do not necessarily propagate from turn to turn and hence the strains measured at the outer support band may be small. A residual compressive force in the magnet windings was also analysed. Ac losses were measured using a 3 MJ pulsed magnet having almost the same structure and conductor as 4 MJ magnet and shown to be fairly small.