Induction acceleration scenario from an extremely low energy in the KEK all-ion accelerator

An all-ion accelerator (AIA)—capable of accelerating all ions of any possible charge state and mass—based on the induction synchrotron concept is under study. This concept was demonstrated in 2006, wherein confinement and acceleration of a proton bunch was independently carried out by the induction cells. In the induction synchrotron based systems, unlike RF synchrotron, the operation frequency of an induction cell is not a limitation, since it generates acceleration voltage by generating trigger signals in synchronization with the bunch signal from the monitors. For the proof of principle experiment of AIA, argon ions is planned to be accelerated in the KEK-PS booster ring (KEK-BR). KEK-BR, operated as a rapid cycle synchrotron at 20 Hz frequency, requires a dynamic acceleration voltage throughout acceleration period. The acceleration voltage pulse provided by the induction cells is fixed in amplitude; therefore a new acceleration scheme using fixed output voltage from the induction acceleration cells is worked out using simulations. This paper discusses the new acceleration scheme for the AIA, its simulation results and a new induction cell giving long acceleration voltage pulse required for AIA. Then various issues are discussed from the practical point of view.