Design of an RF input coupler for the IFMIF/EVEDA RFQ linac

IFMIF/EVEDA加速器系高周波四重極加速器のための高周波結合系の設計

前原 直

Maebara, Sunao

In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a coupled cavity type of RFQ, which has a longitudinal length of 9.78 m, was proposed to accelerate deuteron beam up to 5 MeV. The operation frequency of 175 MHz was selected to accelerate a large current of 125 mA in CW mode. The driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. As the RF input coupler design, RF losses including RF vacuum windows, based on a 4 1/16 inch and 6 1/8 inch co-axial waveguide as well as RF coupling factor of a loop antenna with varied insertion depths using an RFQ model were calculated. In this conference, these results and thermal analysis results in CW operation mode will be presented in details.