Patent ID: 7355189

Claim:
A charged particle therapy system including a charged particle beam generator for generating a charged particle beam and a charged particle beam irradiation apparatus, wherein said charged particle beam irradiation apparatus comprises a casing, a range modulation wheel device arranged in said casing and through which the charged particle beam emitted from said charged particle beam generator passes, a holding member for holding said range modulation wheel device in such a manner that the range modulation wheel device can be inserted into and removed from said holding member, and a range modulation wheel driver having a first rotary shaft, said range modulation wheel device comprising a range modulation wheel having a second rotary shaft in contact with said first rotary shaft and through which the charged particle beam passes, and a housing in which said range modulation wheel is disposed and rotatably mounted and configured to position said range modulation wheel in the charged particle beam irradiation apparatus by contact with said casing or said holding member.