LONGITUDINAL ELECTRIC FIELD IN SUPERCONDUCTORS.

The spatial distribution of the electric field E is calculated in a system comprising a normal metal and a superconductor (N-S) when a constant current is flowing through this system. It is shown that the field E penetrates into the S-region. It is also shown that in the presence of a temperature gradient in the N-S system the S-region contributes to the thermal EMF. The spectrum of the oscillations of E in the superconductor is also calculated. Near the critical temperature the oscillations of E are slightly damped and have an acoustic spectrum omega equals kV.