HE-3-A1 DEFECTS CROSSING THE A1-A2 PHASE-BOUNDARY

The fate of topologically stable defects in the 3He-A 1 phase, which exists in a magnetic field, is analysed when this phase goes over to the A2 phase at lower temperatures. It is shown that in magnetic fields that are not too large the A1 monopoles become confined in the A2 phase. It is argued that the Mermin-Ho relation breaks down in the presence of vortons.