Acoustic Emission by Quartz Tuning Forks and Other Oscillating Structures in Cryogenic 4He Fluids
Acoustic Emission by Quartz Tuning Forks and Other Oscillating Structures in Cryogenic 4He Fluids
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DOI：
10.1007/s10909-011-0353-1
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发表时间：
2011-06-01
影响因子：
2
通讯作者：
Skrbek, L.
中科院分区：
文献类型：
--
作者：
Schmoranzer, D.;La Mantia, M.;Skrbek, L.
我们报告的实验研究的声发射石英音叉谐振频率为32 kHz，38 kHz，77 kHz和100 kHz浸没在冷气态He-4和其正常和超流液相。在350 mK下观察到的低驱动线宽的频率依赖性以及温度和压力依赖性（1.3 K < T < 4.2 K，0 < p < 25 bar）的高频阻尼（77和100 kHz）谐振器测量正常液体氦-4和它的超流体相提供了强有力的和直接的证据，这些音叉的声音发射的重要性。建立了音叉振动声发射的三种解析模型，并与实验结果进行了比较。我们还讨论了常用的32 kHz音叉，以及其他振荡结构的球体，电线，网格和各种微机械传感器的实验的声音发射的重要性。我们比较了由于层流粘性/弹道阻力和声发射在液体和超流He-4的耗散损失的相对重要性。
We report on experimental investigations of acoustic emission by quartz tuning forks resonating at frequencies 32 kHz, 38 kHz, 77 kHz and 100 kHz immersed in cold gaseous He-4 and its normal and superfluid liquid phases. Frequency dependence of the observed low-drive-linewidth at 350 mK together with the temperature and pressure dependences (1.3 K < T < 4.2 K, 0 < p < 25 bar) of the observed damping of the high frequency (77 and 100 kHz) resonators measured in normal liquid He-4 and its superfluid phase provide strong and direct evidence of the importance of sound emission by these tuning forks. Three analytical models of acoustic emission by vibrating tuning forks are developed and compared with the experimental results. We also discuss the importance of sound emission for experiments with the commonly used 32 kHz tuning forks as well as other oscillating structures-spheres, wires, grids and various micromachined sensors. We compare the relative importance of dissipative losses due to laminar viscous/ballistic drag and acoustic emission in liquid and superfluid He-4.