Characterization techniques for fixed-field alternating gradient accelerators and beam studies using the KURRI 150 MeV proton FFAG

S L Sheehy,S Machida,Y Mori,T Uesugi,C R Prior,D J Kelliher,L Volat,Y Kuriyama,C Rogers,Y Ishi,M Haj Tahar,M Sakamoto

doi:10.1093/ptep/ptw086

Abstract

In this paper we describe the methods and tools used to characterize a 150 MeV proton scaling Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University Research Reactor Institute. Many of the techniques used are unique to this class of machine and are thus of relevance to any future FFAG accelerator. For the first time we detail systematic studies under- taken to improve the beam quality of the FFAG. The control of beam quality in this manner is crucial to demonstrating high power operation of FFAG accelerators in future.

Highlights

The first fixed field alternating gradient (FFAG) accelerators were constructed in the 1950s and 1960s as part of the MURA project [1]
In this paper we have described a series of experiments and techniques to characterize the 150 MeV
We have identified key diagnostics and outlined their use in various measurements in this class of accelerator, introducing variations on existing accelerator diagnostics such as the radially movable triangle BPM

Summary

Introduction

The first fixed field alternating gradient (FFAG) accelerators were constructed in the 1950s and 1960s as part of the MURA project [1]. Only electron machines were constructed at the time, no hadron machines Interest in this type of accelerator for hadrons has been revitalized since the late 1990s with technological developments such as low Q RF cavities and precise 3D modeling of magnets. FFAG accelerators could sustain a high average current thanks to their use of DC magnets, which allows an increase in the repetition rate limited only by the RF system. This could result in a higher average current than a synchrotron while operating with a similar or lower bunch charge. Operating an FFAG with a similar bunch charge and space charge tune shift as a synchrotron would produce a much greater beam power than existing machines

Objectives

Discussion

Conclusion