Quartz Tuning Fork Viscometers for Helium Liquids
Quartz Tuning Fork Viscometers for Helium Liquids
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用于氦液体的石英音叉粘度计
DOI：
10.1023/b:jolt.0000035368.63197.16
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发表时间：
2004
影响因子：
2
通讯作者：
J. Owers
中科院分区：
文献类型：
--
作者：
D. Clubb;O. Buu;R. Bowley;R. Nyman;J. Owers
振弦或扭转振荡器形式的机械谐振器长期以来一直被用作液体 3He 和 3He-4He 混合物中的传感器。谐振器的阻尼是由周围液体的粘度引起的，对于大块费米液体来说，粘度是众所周知的强温度函数。因此，可以在毫开尔文范围内使用粘性阻尼进行测温。另一种传感器是小型石英音叉，它由压电效应驱动，不需要外部磁场。在本文中，我们展示了这种音叉浸入 6.2% 3He-4He 混合物中（3 至 100 mK 之间）以及零磁场和高磁场 (10 T) 时的粘性阻尼测量结果。测量结果表明，音叉共振的阻尼主要由液氦特性决定，并且对所施加的磁场不敏感。音叉对饱和氦混合物的响应表明它有可能用于任何磁场中的测温。有证据表明叉子和氦气之间的界面存在滑动，表明来自石英光滑表面的镜面散射。该音叉还能够检测纯液体 3He 中的超流体转变。
Mechanical resonators, in the form of vibrating wires or torsional oscillators, have long been employed as sensors in liquid 3He and 3He–4He mixtures. The damping of resonators is due to the viscosity of the surrounding liquid which is a strong, well-known function of temperature for bulk Fermi liquids. It is therefore possible to use the viscous damping for thermometry in the millikelvin regime. An alternative sensor is the small quartz tuning fork which is driven by the piezoelectric effect and requires no external magnetic field. In this paper, we present measurements of the viscous damping of such a tuning fork when immersed in a 6.2% 3He–4He mixture, between 3 and 100 mK, and at zero and high (10 T) magnetic field. The measurements indicate that damping of the tuning fork resonance is dominated by the liquid helium properties and is insensitive to the applied magnetic field. The response of the tuning fork to the saturated helium mixture demonstrates that it could potentially be used for thermometry in any magnetic field. There is evidence of slip at the interface between the fork and the helium suggesting specular scattering from the smooth surface of the quartz. The fork is also able to detect the superfluid transition in pure liquid 3He.