Patent ID: 8106371

Claim:
A charged particle irradiation system, comprising: an ion beam generator in which a target beam current value is set and from which an ion beam is extracted with the target beam current value; an irradiation nozzle for irradiating an irradiation object with the ion beam, the irradiation nozzle including: a scanning magnet for scanning an ion beam passing therethrough; and an energy filter for increasing a width in a depth direction of a bragg peak formed by the ion beam; and an irradiation object monitoring unit for measuring a position of the irradiation object and outputting signals that vary with time according to displacement of the irradiation object; wherein the charged particle irradiation system determines extraction timing of the ion beam based on the signal outputted from the irradiation object monitoring unit and sequentially changes energies of the ion beam and performing a repainting irradiation with at least one of the energies.