Ultrasonic attenuation in copper at low temperatures

Ultrasonic attenuation in copper at low temperatures has been analysed in terms of electron-electron and electron-phonon interactions. The contribution due to electron-electron interactions has been evaluated using a simplified spherical Fermi-surface model with an isotropic Umklapp transition probability. We observe that the contribution to the attenuation constant (α) due to electron-electron scattering in copper at 3 K is about 10% of the electron-phonon contribution. We have also considered the viscous attenuation and the induction attenuation mechanisms simultaneously in copper as suggested by Orlov and find that our results improve the existing theoretical data considerably.