Probe measurements of the parameters of the electron component in the accelerators with closed drift of electrons

摘要

Summary form only given. During the research of the discharge characteristics of the accelerator from the closed drift of electrons (as an experimental ion source of the "Radical" type has been used), the stationary character of the electronic current has been determined. To understand the mechanism of the electron leaving the cathode, a series of experiments on probe diagnostics of the electronic component in the anode layer has been made. For this purpose a plate probe (PP) on the surface of the cathode and miniature mobile thermoprobe (TP) have been used. Both for the discharge characteristics and for the local parameters of the electron component depending on the magnetic field two typical regimes can be distinguished: regime 1, with H>H* where H* is some critical value and regime 2, with H10/sup -4/ Torr. The electron energy distribution function(EEDF) does not have Maxwell type. In the regime 2: I/sub pe2//spl Lt/I/sub pe1/; EEDF has Maxwell kernel with typical values of electron temperature T/sub e/=10-50 eV. If H increases I/sub pe/, T/sub e/ and values of the locking voltage U/sub o/ increases too. Transfer from one regime to another occurs discontinuously.