Scaling fixed-field alternating gradient accelerators with a small orbit excursion.
A novel scaling type of fixed-field alternating gradient (FFAG) accelerator is proposed that solves the major problems of conventional scaling and nonscaling types. This scaling FFAG accelerator can achieve a much smaller orbit excursion by taking a larger field index k. A triplet focusing structure makes it possible to set the operating point in the second stability region of Hill's equation with a reasonable sensitivity to various errors. The orbit excursion is about 5 times smaller than in a conventional scaling FFAG accelerator and the beam size growth due to typical errors is at most 10%.
Machida
Shinji
S
ASTeC, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX, United Kingdom. shinji.machida@stfc.ac.uk