View
216
Download
0
Tags:
Embed Size (px)
Citation preview
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
nsFFAG
Bending by dipoles, focussing by quadrupolesAs beam momentum rises, dipole field rises so bending power the sameFocussing power stays the same if and only if quadrupole field rises proportional to momentum. Then optics stays the sameThis is ‘scaling’Easy to achieve with synchrotron: dipoles and quadrupoles have same current.Severely constrains geometry of FFAG fields, B ~ rk
nsFFAG: will it workOptics changes during the acceleration cycle:
focussing and bending are not linkedTune 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…