Patent ID: 8153990

Claim:
A particle beam therapy system comprising: an accelerator for accelerating a charged particle beam such that the charged particle beam has a predetermined energy level to be extracted; an irradiation device for irradiating an irradiation target with the charged particle beam; a beam transport system having a bending magnet for introducing the charged particle beam which has been extracted from said accelerator into said irradiation device, the bending magnet bending the charged particle beam; and a beam interrupting device provided in the beam transport system and blocking supply of the charged particle beam to said irradiation device; wherein said accelerator includes an extraction deflecting magnet for bending the charged particle beam accelerated to said predetermined energy level to extract the charged particle beam from said accelerator into said beam transport system, and wherein said beam interrupting device includes a beam shielding magnet and a beam dump, the beam shielding magnet being located on an upstream side of the bending magnet with respect to the direction of flow of the charged particle beam in said beam transport system and is for bending the charged particle beam extracted from said accelerator by said extraction deflecting magnet upon blocking the supply of the charged particle beam to said irradiation device, and the beam dump being located on a downstream side of the bending magnet with respect to the direction of the flow of the charged particle beam.