Torsional stress pulses of several microseconds duration were applied at 4.2 °K to cylindrical single crystals of copper containing freshly introduced dislocations. Dislocation displacements were measured by means of a double-etch technique, and subsequently the dislocation damping coefficient $B$ was determined to be equal to 0.8 × ${10}^{-5\mathrm{}}$ dyn sec/${\mathrm{cm}}^2$. While $B$ decreases monotonically with decreasing temperature, the value of $B$ at 4.2 °K is greater than that predicted from theoretical calculations of the interaction between a moving dislocation and the conduction-electron gas in copper.

• Received 14 February 1972

DOI:https://doi.org/10.1103/PhysRevB.8.3537