High Transition Energy Magnet Lattices

Several methods have been investigated to raise the transition energies of the TRIUMF KAON Factory accelerators, designed to provide 100 μ A proton beams at 30 GeV, above their acceleration ranges. This would completely avoid beam loss at transition, which, even at the few percent level, would be unacceptable for these beam currents. The methods require a periodic perturbation in either the bending properties of the lattice or the focusing properties or both. In a combined-function lattice the perturbation is provided by clustering the magnets within each superperiod. The effects on the lattice functions are described. The long drifts resulting from the magnet distribution provide natural gaps for beam extraction and injection elements and for rf accelerating cavities.