title: Primary and secondary nucleation of the transition between the A and B phases of superfluid 3He
abstract: We have studied nucleation in superfluid 3He across the A-B phase transition driven by a magnetic field, in a controllable environment at very low temperatures. Both B-->A and A-->B secondary nucleation appear to be governed by the survival of pockets of the new phase trapped at surfaces. We find that, at fields near B(AB), primary A-->B nucleation cannot be triggered by ionizing or neutron irradiation even at very high intensities. In our cell primary A-->B nucleation can only be triggered externally by mild mechanical shock.
authors.affiliation: Department of Physics, Lancaster University, Lancaster, LA1 4YB, United Kingdom.
authors.initials: M
authors.lastname: Bartkowiak
authors.initials: SN
authors.lastname: Fisher
authors.initials: AM
authors.lastname: Guenault
authors.initials: RP
authors.lastname: Haley
authors.initials: GR
authors.lastname: Pickett
authors.initials: GN
authors.lastname: Plenderleith
authors.initials: P
authors.lastname: Skyba