Non-collinear acoustic attenuation of transverse waves

Simple quantum mechanics and complicated ultrasonic attenuation

“…Thus collisions occur only where 8 > 0 and where [Ql > 0 reducing the contribution from the central peak of the probability distribution and leading to a balanced contribution from both the central maximum and the tail, and a temperature dependance T" where 4 < n < 9 for the fast shear wave. A detailed calculation along these lines has been carried out, using a realistic model for the angular dependance of the third order elastic constants, and a numerical integration over the thermal phonon distribution[ 5 ] . The results do give a T7 dependance and are in excellent agreement with the experimental results for the fast shear wave.Slow shear waves can have interaction with the fast transverse wave and have vgth/v, > 1.…”