A-B PHASE-TRANSITION IN ROTATING SUPERFLUID HE-3

Quantized vortices, when formed in rotating He-3, can effectively be s tudied by NMR. Vortices of different structure have been identified, d epending on the superfluid phase and the external conditions. Here we discuss what happens when the first-order phase boundary, which separa tes the A and B phases, traverses through a rotating container which i nitially contains an equilibrium vortex array. The measurements imply that a vortex layer is formed in front of a slowly propagating interfa ce and part of the newly formed phase behind the interface is left dev oid of vortices.