Study of modified TBA driver scheme

Abstract

A modified scheme of two beam accelerator (TBA) [1] driver based on a linear induction accelerator is studied in this paper. In the proposed scheme the electron beam bunching occurs at a rather low initial energy ~ 1 MeV. The bunched beam is accelerated in the accompanying enhanced synchronous microwave that provides the steady longitudinal beam bunching along the whole driver. There is no total microwave power extraction anywhere in the driver. A waveguide (initially corrugated and regular further) is used along the driver [2]. The simulation showed that a steady state is achieved when electron bunches accompanied after a TWT by an amplified microwave are simultaneously accelerated in an external electric field both for continuously distributed system parameters and for discrete parameters of accelerating sections. In the steady state the whole power, which is inserted into the beam by the accelerating field, transforms into the microwave power. Such kind of systems can serve effectively as a rather long (hundreds of meters) driver for the TBA concept. The experimental setup based on the JINR LIA-3000 facility to test the new scheme is under construction at present. It consists of the 800 keV, 200 A injector and two reaccelerating sections. The first experimental results of the beam bunching study have been presented.