Observation of phase advance due to diffraction of ultrasonic pulse.
Observation of phase advance due to diffraction of ultrasonic pulse.
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观察超声波脉冲衍射引起的相位超前。
DOI：
10.1250/ast.1.11
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
H. Ozawa
中科院分区：
文献类型：
--
作者：
K. Negishi;K. Takagi;H. Ozawa
脉冲回波重叠法已被应用于检测由于衍射相位提前。两个电极半径为5 mm的石英换能器已被用于单向路径长度为62 mm的发射-接收系统。在3 MHz和9 MHz频率下，以甲醇-水混合物为介质，进行了不同浓度的实验。当速度为1497 m/s时，在3 MHz下测得的往返旅行时间比在9 MHz下测得的短14.5ns。已检测到的旅行时间的倒数的差异，并绘制为速度的函数。衍射理论很好地描述了结果的轮廓。然而，实验曲线具有周期性出现的小峰，这不能用衍射理论或波导理论预测。进一步的实验表明，这些峰值与有限的声传播空间有关，但没有给出明确的解释。
Pulse-echo-overlap method has been applied to detect the phase advance due to diffraction. Two quartz transducers with electrodes 5mm in radius have been used for a transmitter-receiver system with one-way path length 62mm. Experiment has been made at 3MHz and 9MHz in methanol-water mixture as varying its concentration. Roundtrip travel time obtained at 3MHz is by 14.5ns shorter than the value at 9MHz when the velocity is 1497m/s. The difference in reciprocal of the travel time has been detected and plotted as a function of velocity. Outline of the results is described well by diffraction theory. The experimental curve has, however, small peaks occurring periodically, which can not be predicted with diffraction theory nor with wave-guide theory. Further experiment made using a cell with larger inner diameter suggests these peaks are some what related to the limited space of sound propagation, but clear explanation has not been given.