Compact high current proton cyclotron and associated beam dynamics

A compact proton cyclotron of 1 MeV, 5mA is being developed at VECC is an R&D project to study and settle various problems related with the transport, injection and acceleration of high current beams in a cyclotron. Proton beam from 2.45 GHz microwave ion source (already operating with 8mA @ 80 keV) will be first bunched using a sinusoidal buncher and then will be injected axially in the central region of the cyclotron where a spiral inflector will place the beam on the proper orbit. In this paper we discuss the design of the magnet of 1 MeV cyclotron, simulation results of beam transmission through the spiral inflector and the results of studies on the behaviour of transverse envelopes of space charge dominated beam along the accelerated orbits. Efforts have been made to obtain the proper matching conditions at the central region by optimizing the input beam parameters of the injected beam. The maximum beam current that can be accelerated through the available aperture of the cyclotron focusing channel has also been estimated.