Secondary emissive double layer in beam-plasma system

The emissive characteristics of the boundary layer arising on a plasma target bound in a beam-plasma system with the presence of secondary electron emission which is conditioned by the action of an electron beam were experimentally and theoretically investigated. The layer was studied by the probing flow of thermionic electrons injected from the target side. The Langmuir model of the layer with the allowance for the presence of the electron beam was used for a theoretical description of the boundary layer. A condition of secondary emissive double layer existence was obtained. It was shown that the double layer appearance led to the limitation of electron emission from the target at a considerably lower level than that in the case viewed by Langmuir.