Plasma anisotropy upon emission of charged particles

Anisotropic perturbation of the plasma of a hollow-cathode reflex discharge is experimentally studied upon emission of electrons through the axial channel of the reflecting cathode. The energy spectrum of emitted electrons is broadened along the emission direction when the external accelerating field is increased. The spectral broadening is related to the directional motion of plasma electrons toward the emitting surface of plasma. Axial gradients of concentration and electric potential are possible reasons for the directional motion of electrons.