Variable energy radio frequency quadrupole linac

摘要

A variable energy radio frequency quadrupole linac for emitting focused and accelerated beams by changing radio frequency energy levels, wherein the accelerating cavity is divided by a plane perpendicular to the beam direction and in a radio frequency sense, and the radio frequency power level in the downstream accelerating cavity is made to be lower than that in the upstream accelerating cavity, one of the divided cavities being self oscillated, and the other being separately oscillated, a separating plate being provided between separated electrodes, the radio frequency phases in the upstream cavity and the downstream cavity being relatively changeable, and a thin plate region being provided in the periphery of a beam passing window on the separating plate, thereby the power in the cavity can be lowered without expanding the energy spread of the emitted beams so much.