Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Measurements on a dynamic A-B phase boundary in superfluid He-3 at very low temperatures.
AU - Fisher, Shaun N.
AU - Guénault, A.M.
AU - Haley, Richard P.
AU - Pickett, George R.
AU - Plenderleith, G. N.
AU - Skyba, P.
PY - 1998/12
Y1 - 1998/12
N2 - We present preliminary measurements of the dynamics of a moving A-B phase interface in superfluid He-3 art temperatures below 0.2T(c). We initially stabilise the interface at lour temperatures with a shaped magnetic field. We can then move the interface in a controlled manner by applying small additional time-dependent fields. The interface is created inside a quasiparticle radiator consisting of a cylindrical chamber in weal thermal contact with the refrigerant. Vibrating wire resonators inside the radiator allow us to monitor the temperature of the superfluid and to infer the heat generated by the interface motion. When me oscillate the interface at low frequencies, we measure spectacular oscillatory swings of the liquid temperature arising from the enormous change in the low lying density of states as the volume of the A-phase superfluid is alternately compressed and expanded. We have also observed hysteresis in the transition as a function of magnetic field. In particular, we observe a small history-dependent 'super-magnetisation' of the B-phase prior to A-phase nucleation in the experimental chamber. When the system is in the metastable super-magnetised state we are able to observe a higher nucleation probability of the A-phase when the cryostat is exposed to neutrons.
AB - We present preliminary measurements of the dynamics of a moving A-B phase interface in superfluid He-3 art temperatures below 0.2T(c). We initially stabilise the interface at lour temperatures with a shaped magnetic field. We can then move the interface in a controlled manner by applying small additional time-dependent fields. The interface is created inside a quasiparticle radiator consisting of a cylindrical chamber in weal thermal contact with the refrigerant. Vibrating wire resonators inside the radiator allow us to monitor the temperature of the superfluid and to infer the heat generated by the interface motion. When me oscillate the interface at low frequencies, we measure spectacular oscillatory swings of the liquid temperature arising from the enormous change in the low lying density of states as the volume of the A-phase superfluid is alternately compressed and expanded. We have also observed hysteresis in the transition as a function of magnetic field. In particular, we observe a small history-dependent 'super-magnetisation' of the B-phase prior to A-phase nucleation in the experimental chamber. When the system is in the metastable super-magnetised state we are able to observe a higher nucleation probability of the A-phase when the cryostat is exposed to neutrons.
KW - A-PHASE
KW - B-PHASE
KW - BOUNDARY
U2 - 10.1023/A:1022541125193
DO - 10.1023/A:1022541125193
M3 - Journal article
VL - 113
SP - 651
EP - 659
JO - Journal of Low Temperature Physics
JF - Journal of Low Temperature Physics
SN - 0022-2291
IS - 5-6
ER -