Design of RF cavity test module for electron accelerator with magnetron 2.45 GHz

Abstract

A design of low-cost electron accelerator is currently being initiated by utilizing a magnetron that is widely commercially used. One such activity is designing an RF cavity test module consisting of a magnetron as an RF source, a waveguide to transfer the RF waves, a cavity where the RF waves resonate and a coupling as a connecting bridge between the cavity and the waveguide. Starting with selecting a magnetron, it was decided to use the commercial magnetron which has an operating frequency of 2.45 GHz. The next stage is to design the cavity. By using CST Studio software, a series of executions using parameter sweep was carried out to obtain the optimal cavity dimension. This leads to a cavity that is 4.74 cm in radius and 3.96 cm in width. These dimensions generate an eigenfrequency of 2.450 GHz and a maximum electric field of 225.7 MV/m by normalizing the stored energy to 1 Joule. To transfer RF waves, a W340 type waveguide is selected. Concerning the coupling, simulation by CST Studio gives iris dimensions of 3.31×0.90 cm2 as the best design. These dimensions give a coupling efficiency of 5.51 and a maximum electric field of 216.4 MV/m.