# Scaling Fixed-Field Alternating-Gradient accelerators with reverse bend and spiral edge angle

## TL;DR

This paper introduces a new design for scaling FFAG accelerators that combines reverse bend magnets and spiral edge angles to improve vertical focusing, enabling high-energy applications like proton drivers for neutron sources.

## Contribution

It proposes a novel scaling FFAG design integrating reverse bend and spiral edge angles to address limitations of conventional designs.

## Key findings

- Design enables high-energy proton acceleration above GeV.
- Improves vertical focusing without extreme parameter values.
- Suitable for applications like neutron sources and subcritical reactors.

## Abstract

A novel scaling type of Fixed-Field Alternating-Gradient (FFAG) accelerator is proposed that solves the major problems of conventional scaling FFAGs. This scaling FFAG accelerator combines reverse bending magnets of the radial sector type and a spiral edge angle of the spiral sector type to ensure sufficient vertical focusing without relying on extreme values of either parameter. This new concept makes it possible to design a scaling FFAG for high energy (above GeV range) applications such as a proton driver for a spallation neutron source and an accelerator driven subcritical reactor.