| 摘要 |
PURPOSE:To obtain a signal equlvalent to one transmitting a specimen with the reflection constitution unchanged and to obtain the one-dimensional distribution of the acoustic velocity of the specimen by an interference method by lining a living specimen with a material having a large acoustic impedance. CONSTITUTION:The specimen 100 is so constituted that it is held by two Mylar filmes and its back side is made of air, with the use of a multi-layered structure specimen stand 110 made of metal M glass and its acoustic impedance is large than that of the specimen. Thus the most part of a ultrasonic beam incident on the upper surface l1 of the specimen 100 is propagated into the specimen 100, reflected on the interface l2 of the specimen stand 110, and detected by a lens system 140 through a water 130 from the specimen upper surface l1. The reflected signal is equivalent to the signal transmitting twice the specimen 100. If a distance between the lens system and the specimen is moved, the local minimum point of the detecting signal appears one by one, whereby the acoustic distribution of the specimen can be obtained by measuring the shift of an interference fring caused by the interference method. |
