Development of powerful Ka-band FEM-amplifiers with broad frequency tuning

摘要

During the several preceding years, an oscillatorscheme of a free electron maser (FEM) has been realizedin the joint experiments between JINR (Dubna) and IAPRAS (Nizhny Novgorod) [1]. The project was aimed ataccelerating applications, and the FEM operates in a fre-quency range of 30 GHz and generates 20 MW / 200 nspulses with a spectrum width of 6–7 MHz, which is closeto the theoretical limit. The high output power and stabil-ity of a narrow-band operation regime allowed this JINR-IAP FEM to be used in a number of actual demand appli-cations, including testing the components of high-gradient accelerators of the next generation [2].However, many potential applications of powerfulmicrowave sources require an RF-radiation phase to becontrolled. Moreover, some applications need a broadinstantaneous amplification band or a fast frequency tun-ing. In particular, for accelerating applications, precisematching of the radiation frequency with the frequency ofhigh-gradient structure should be provided. For this pur-pose, the FEM-amplifier project is developed based onLIU-3000.