标题： 超声波的相干后向散射无源 显示英文标题

标题： Coherent backscattering of ultrasound without a source

摘要： 相干背向散射是由于互易路径的建设性干涉导致的，并导致在源附近多次散射场的强度增强。 为了观察这种增强，通常将接收器阵列放置在源附近。 我们在这里的方法不同。 在第一个实验中，我们使用扩散场的时间相关性，在源阵列和远距离接收器中恢复相干背向散射效应（CBE）。 增强锥具有良好的空间分辨率。 在第二个实验中，使用相同超声频率下的热声子相关性研究增强因子的动力学，没有任何主动源。 显示英文摘要

摘要： Coherent backscattering is due to constructive interferences of reciprocal paths and leads to an enhancement of the intensity of a multiply scattered field near its source. To observe this enhancement an array of receivers is conventionally placed close to the source. Our approach here is different. In a first experiment, we recover the coherent backscattering effect (CBE) within an array of sources and a distant receiver using time correlation of diffuse fields. The enhancement cone has an excellent spatial resolution. The dynamics of the enhancement factor is studied in a second experiment using correlation of thermal phonons at the same ultrasonic frequencies, without any active source.