Transverse Acoustic Response Measured by AC-cut Quartz Transducer in Superfluid Helium-3

摘要

The transverse acoustic response in the B phase of superfluid 3He has been measured using an AC-cut quartz transducer at a pressure of 17.0 bar. The measurements were performed by a CW bridge method at a frequency of 9.3 MHz utilizing a quadrature hybrid and a high-frequency lock-in amplifier. By sweeping frequency around the resonance frequency of the transducer, in-phase and quadrature responses of the resonance were obtained from the output of the lock-in amplifier. We successfully separated the quality factor and the resonance frequency. Quality factor of the transducer had a small dip just below Tc and increased as ρn by cooling, while its resonance frequency decreased sharply at Tc and gradually recovered to the normal state value in the low temperature limit.