Acoustic microscope using pressurized superfluid 4He
Acoustic microscope using pressurized superfluid 4He
复制标题
使用加压超流体 4He 的声学显微镜
DOI：
10.1063/1.345636
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Y. Okuda
中科院分区：
文献类型：
--
作者：
K. Karaki;Masaru Suzuki;Y. Okuda
利用超流氦作为声耦合介质，研制了一种声显微镜。声学显微照片，采取使用纯超流4 He在饱和蒸汽压在0.1 K和25大气压下在0.1和1.9 K，频率为380 MHz。通过对液体4 He加压，声衰减减小，超流涂层的效率增加，并且由超流4 He的非线性引起的饱和的功率水平提高。因此获得了成像的良好信噪比。整个成像仪器组都在一个封闭的单元内。聚焦机构由两个超导线圈音圈组成。使用带有传感器和驱动线圈的伺服控制机构，Z方向稳定性优于0.05 μm。操作灵敏度为0.5 μm/mV，整个行程约为2 mm。
An acoustic microscope has been developed which makes use of pressurized superfluid helium as an acoustic coupling medium. Acoustic micrographs were taken using pure superfluid 4He under saturated vapor pressure at 0.1 K and under 25 atm at 0.1 and 1.9 K, for the frequency of 380 MHz. By pressurizing liquid 4He, the acoustic attenuation decreases, the efficiency of the antireflection coating increases, and the power level of saturation caused by nonlinearity of the superfluid 4He is raised. A good signal‐to‐noise ratio of imaging is thus obtained. The entire imaging instrument set is within a closed cell. The focusing mechanism is composed of two voice coils of superconducting wire. Using a servocontrol mechanism with a sensor and drive coil, Z‐direction stability was better than 0.05 μm. The manipulation sensitivity is 0.5 μm/mV, and the whole stroke is about 2 mm.