  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.
