Simulation of the electromagnetic field in a rectangular multimode chamber of a 14GHz ion source

Abstract

Electron cyclotron ion sources producing multicharged ion beams of high intensity are widely used in scientific and industrial technologies. To multiply ionize heavy atoms. the electron component of a plasma confined in a magnetic trap is energized by microwaves in the cyclotron resonance conditions. The design of the existing sources does not permit determining the microwave field caracteristics which are responsible for the electron component heating and consequently for the performance of the source. In this work we present a numerical study of the microwaves propagation from a magnetron generator to a multimode rectangular chamber through a rectangular waveguide and an aperture. The electromagnetic energy from a magnetron with frequency of 14GHz works as microwave source is coupled by a rectangular waveguide through an aperture. The evolution of the stationary microwave field in the chamber is calculated using the Yee’s method through a subrouting based on the numerical solution of Maxwell’s equations which uses the Yee’s method. The results show that the spatial distribution of the electromagnetic field is appropriate for the plasma heating, due to the uniformity of electric field maximums on the resonance surface. The precision of the numerical calculation is verified through the calculation of the divergences of both the electric and magnetic fields.