New method for control of longitudinal emittance during transition in proton synchrotrons

A new method for controlling longitudinal emittance growth during transition crossing in proton or heavy ion synchrotrons is described. Longitudinal focusing forces are eliminated near transition through the use of RF harmonics. The RF system provides only the required accelerating voltage to each particle in each bunch during the nonadiabatic period near transition, hence momentum growth is minimized. Bunch length is maximized just at transition, minimizing space charge forces and associated instabilities.<
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