Particle-beam energy changing apparatus, particle beam therapy system including the same, and method of changing particle beam energy

摘要

There is provided a particle-beam energy changing apparatus that is capable of changing energy of a particle beam quickly and silently, in which a first energy changing unit and a second energy changing unit for changing energy of a particle beam passing therethrough by varying thicknesses of their attenuators attenuating the particle beam energy are arranged so that the particle beam passes through the first energy changing unit and the second energy changing unit; and the maximum attenuation amount by the first energy changing unit is set smaller than the maximum attenuation amount by the second energy changing unit.

主权项

1. A particle-beam energy changing apparatus comprising:
a first energy changing unit and a second energy changing unit each having a particle-beam energy attenuator and arranged so that a particle beam passes through the first energy changing unit and the second energy changing unit, to change energy of the passing particle beam by varying thicknesses of the attenuators; and an energy-change substitution control unit which controls the first energy changing unit and the second energy changing unit, wherein a maximum attenuation amount by the first energy changing unit is set smaller than a maximum attenuation amount by the second energy changing unit, and the energy-change substitution control unit is configured to perform a control of changing energy of the particle beam at least by changing an attenuation amount by the first energy changing unit when energy of the particle beam is controlled to change, and a substitution control that substitutes an attenuation amount by the first energy changing unit and an attenuation amount by the second energy changing unit for each other by changing the attenuation amount by the first energy changing unit and the attenuation amount by the second energy changing unit so that a total attenuation amount of the attenuation amount by the first energy changing unit and the attenuation amount by the second energy changing unit remains unchanged when energy of the particle beam after passing through the particle-beam energy changing apparatus is controlled to be constant.