Irradiation Field Forming Device

摘要

An irradiation field forming device for forming an irradiation field when a specimen is irradiated with a charged particle beam generated by an accelerator, the irradiation field forming device includes: a range shifter arranged on a beam axis of the charged particle beam for regulating an irradiation depth of the charged particle beam; and two or more than two converging electromagnets arranged in the downstream of the range shifter for regulating a beam diameter of the charged particle beam which is enlarged by the range shifter to a constant value.