• C. Johnstone
  Fermilab, Batavia
• M. Berz, K. Makino
  MSU, East Lansing, Michigan
• S.R. Koscielniak
  TRIUMF, Vancouver
• F.E. Mills
  PAC, Batavia, Illinois
• P. Snopok
  UCR, Riverside, California

The quest for higher beam power and duty factor and precisely controlled beams at reasonable cost has generated world-wide interest in Fixed-field Alternating Gradient accelerators (FFAGs). A new concept in non-scaling FFAGs to stabilize the betatron tune is under development. The emphasis to date has been on electron and proton accelerators, yet many facilities utilize H^- front ends. This concept naturally extends to H^- FFAGs and under conditions of rapid acceleration, the FFAG functions essentially as a recirculating linac with a common-aperture arc. As such it may be suitable for replacement of aging H^- linac sections. For a slow acceleration cycle, an H^- FFAG machine can exploit H^- techniques to control extraction and intensity, and represents an innovation in proton therapy accelerators. Prototype RF and magnet component design have been initiated. For ten-turn acceleration, the rf cavities in a 10-100 MeV FFAG cannot be re-phased on the revolution time scale, and local adjustment of the pathlength is the proposed approach. For slow acceleration, broad-band, low-frequency rf can be applied. The basic optics and components for such FFAGs are presented.