Modernization of the injector for a multibeam proton accelerator

Abstract

Within the program for the development of high-current charged-particle accelerators with a high acceleration rate, an injector for a 19-beam proton accelerator with a multibeam ion injection mode is described. The injector contains an ion gun with a duoplasmatron-type H2 ion source and a multiaperture ion-optical system regulating the inclination of the ion-beam current tubes at the inputs of the corresponding channels of the accelerating structure. The cold-cathode ion source contains a system for transporting plasma from the cathode to its output aperture in magnetic fields of complex configurations, which allows stable pulsed generation of proton beams with a current amplitude of up to 3 A at an operating gas pressure in the discharge chamber of 0.2 Torr and a decrease in the flow of unionized gas emerging from the source to 2 cm3/h. It is shown that the developed ion source and the ion-optical system make it possible to increase the phase density of the beam current at the inputs of the accelerating-structure channels and to change the divergence angles.