Generalized Formula for Calculating the Electric Field on the Electrode Surface in Plasma

The electric field on the surface of a metal electrode immersed in plasma with an electron temperature of T-e similar to 10 eV and plasma density ne from 10(10) to 10(13) cm(-3) has been calculated under negative electric potential Psi(0) of the electrode and large values of parameter |e Psi(0)|/T-e >> 1. The obtained asymptotic formula for the field strength at |e Psi(0)|/T-e >> 1 differs significantly from the classical formulas for calculating the electric field and the Debye length of field screening near the electrode surface in plasma, which are valid under condition |e Psi(0)|/T-e << 1. It has been shown that, at |e Psi(0)|/T-e >> 1, near the electrode in a plasma, a modified Debye layer can exceed the classical Debye length by two orders of magnitude. To calculate the electric field on the electrode surface in plasma, a generalized formula has been proposed in the explicit form, which is valid in a wide range of parameter 0 < |e Psi(0)|/T-e < 10(4) at negative electrode potentials of up to 10 kV.