Quasi-adiabatic Transition Crossing in the Hybrid Synchrotron

Non-adiabatic features around the transition energy are well-known to be one of most important beam physics issues in most of circular hadron accelerators. A novel technique to avoid them by the adiabatic motion, a quasiadiabatic, nonfocusing transition-energy crossing (QNTC), was proposed. In a longitudinally separated function-type accelerator, in which particles are confined by an rf voltage or burrier voltages and accelerated by a step voltage, the confinement voltage can be arbitrarily manipulated as long as the particles do not diffuse, while a strict acceleration voltage is necessary for the orbit of a charged particle to be balanced in the radial direction. The introduction of QNTC is most suitable for the longitudinally separated function-type accelerator. This new method was examined in this type of accelerator, both theoretically and experimentally. This was a first and significant application of the hybrid synchrotron. The results will be presented.