FFAG

1
FFAG
Ring of magnets, like synchrotron, not solid like
cyclotron Fixed field magnets, like cyclotron,
not variable like synchrotron
Can work at relativistic energies with swept
RF. Rep rate driven by RF acceleration, not
magnet cycling, hence fast acceleration High
duty cycle may be possible. Depends on
longitudinal dynamics
2
nsFFAG
Bending by dipoles, focussing by quadrupoles As
beam momentum rises, dipole field rises so
bending power the same Focussing power stays the
same if and only if quadrupole field rises
proportional to momentum. Then optics stays the
same This is scaling Easy to achieve with
synchrotron dipoles and quadrupoles have same
current. Severely constrains geometry of FFAG
fields, B rk
3
nsFFAG will it work

• Optics changes during the acceleration cycle
  focussing and bending are not linked
• Tune changes during cycle. (Number of betatron
  oscillations per turn)
• Normally integer tune death due to resonances
  lattice imperfection tweaks beam at same point on
  every cycle
• But in the rapid acceleration cycle of an FFAG
  this should not matter.
• Maybe