ENERGY DEGRADER, AND CHARGED PARTICLE IRRADIATION SYSTEM COMPRISING SAME

摘要

Provided is an energy degrader which can reduce the size of a device, and also provided is a charged particle irradiation system which comprises the energy degrader. As attenuation sections (12) for attenuating energy, portions (11) having thicknesses which vary stepwise or continuously are two-dimensionally arranged in a plane which intersects the advancement direction of charged particles. The energy degrader (10) comprises a driving means (40) for translationally driving the attenuation sections in the directions of first and second intersecting axes (X, Y) in a two-dimensional coordinate system. As a result of using the two-dimensionally arranged attenuation sections, the maximum external shape of the attenuation sections is reduced.