The dependence of a plasma acceleration process on a expansion area geometry

It has been reported [1] that plasma acceleration by a electron beam results in a ion energy spectra that coincides with energy ion spectra of a pulsed vacuum discharges. Thus, one can assume that acceleration of plasma by electron beam is the basic plasma acceleration mechanism in a different types of a vacuum discharges. This work is devoted to examination of influence of expansion area geometry on an acceleration process. Experimental setup consist of three different units : 1. vacuum diode; 2. plasma cloud formation unit; 3. expansion unit. Experiments were made for three expansion area configuration : 1. Without expansion unit; 2. Expansion tube;3. Expansion cone. Experiments have shown that narrowing of an expansion area results in additional acceleration of ions. Measurements of an ion energy spectra revealed a high energy tails appearance.