Influence of He-4 Coverage on Resonance Properties of a Quartz Tuning Fork Immersed in Liquid He-3

摘要

Nowadays quartz tuning forks are commonly used for temperature measurements in experiments with liquid (both normal and superfluid) He-3. In most of the experiments pure He-3 is used, but in some cases He-4 is added in order to cover surfaces by a few monolayers of He-4. We report here measurements of influence of different He-4 coverages on the fork resonance properties at different pressures. We have found that the presence of even small amounts of paramagnetic He-3 on the fork surface may essentially change the temperature calibration.