【摘要】 用超声脉冲回波法,在10—250MHz频率范围内和4.2K、77K、300K的不同温度下,测量了石英晶体中沿x轴方向传播的超声縱波的衰减系数,得出了三个温度下的超声衰减与频率的关系曲线,同时作了衍射修正和非平行度效应引起的修正。最后,对实验结果进行了分析和讨论。更多还原

【Abstract】 The frequency dependence of the attenuation of longitudinal ultrasonic waves in synthetic quartz has been measured using the pulse-echo method, with frequencies ranging from 10MHz to 250MHz, at 4.2K, 77K and 300K. The correction of diffraction and nonparallelism effect has been made. It has been found that there is an attenuation peak at frequency 21OMHz at 300K and there are two attenuation peaks at 130MHz, 210MHz, at 77K. The mechanisms of these attenuation peaks are explained. At 4.2K the attenuation of longitudinal ultrasonic waves is independent of frequency.更多还原