New types of negative ion sources

Summary form only given, as follows. The plasma sources of negative ions which were elaborated in Kharkov State University are considered in the paper. These sources use the mechanism of dissociative sticking of electrons with low energies to molecules of the working gas. The effective work of such sources needs the use of special systems of low energy electron formation. The effect of secondary electron emission as used in negative ion sources is considered. The electrode material with large coefficient of secondary electron emission allows one to obtain a few slow electrons per one bombarding electron. The plasma of a Penning discharge is an emitter of initial electrons. The electron electromagnetic trap in the secondary electron emission region allows one to enlarge the volume of interaction of low energy electrons with the working gas molecules. The lifetime of slow electrons grow in this trap.