Helicon propagation in sodium and copper

Helicons and Gantmakher-Kaner oscillations were observed for the sodium metal. For a cylindrically symmetric Fermi surface approximation for copper, we observed the beating of two Gantmakher-Kaner waves for the [111] direction of copper and helicon propagation for the [001] direction of copper. Using the true Fermi surface of copper, we observed helicon propagation in the [001] direction. In all instances of helicon propagation, we found that a relaxation time of 10[raised -10] sec. produced smooth sinusoidal shaped helicon curves, whereas a relaxation time of 10[raised -9] sec. produced a delta-function shaped curve.