Distribution function of slow electrons in a discharge with cylindrical hollow cathode

Shaping the electron distribution function (EDF) is analyzed in a hollow cylindrical cathode in the energy range up to the inelastic processes threshold. It is shown that EDF represents itself the Maxwell distribution in the thermal range and a ''step'', determined by fast electron sources. A specific feature of the EDF is the absence of radial dependence in the total energy scale. The obtained expressions permit simply to calculate the EDF on the base of a given current of the discharge and its geometrical dimensions