RF system design for the EMMA FFAG

Abstract

In this report the RF system design for EMMA (Electron Machine with Many Applications) is described. EMMA is a proof of principle Non-scaling FFAG that adopts an acceleration scheme will prove useful for fast acceleration of particles. For instance in medical applications, such as Hadron Therapy and future neutrino factory designs for Muon acceleration. The worlds first accelerator of this kind is currently under construction at Daresbury Laboratories. The EMMA RF power source options, power supplies, waveguide distribution scheme and control system is discussed. The nature of the machine requires a large degree of adjustment and flexibility than compared with conventional accelerators. So, to enhance the versatility of this machine, a complex RF system has been designed. This report details the RF schematic included to meet this requirement. This accelerator requires a bespoke RF Cavity, a complex distribution scheme from a single RF source to 19 cavities and a low level RF control system to provide sufficient operating conditions for the accelerator. In order to meet the budget, a number of developments were required to minimize RF power requirements. A design is now under construction that will provide the full flexibility of the machine parameters This includes an efficient cavity and coupler design, low loss distribution and pulsed RF source. A digital low level RF system has been developed to provide within 0.3 degrees and 0.3% phase and amplitude control. This has been modelled and demonstrated, and is currently under construction. An overview of the design requirements for each part of the system will be provided including any improvements on the specification. (3 pages)