Patent ID: 9101763
Filing Date: 2015-08-11
Classification: A61N

Abstract:
1. A particle beam irradiation apparatus that irradiates a charged particle beam accelerated by an accelerator onto an irradiation subject, the particle beam irradiation apparatus comprising: a vacuum duct that forms a vacuum region through which the charged particle beam passes; a vacuum window that includes a nonmetallic window plate, and is provided at the downstream side of the vacuum duct and through which the charged particle beam is launched from the vacuum region; a scanning electromagnet that scans the charged particle beam in a direction that is perpendicular to a beam axis; a monitoring apparatus including a position monitor that detects a passing position of the charged particle beam and a beam size thereof; a low-scattering gas filling chamber that covers the vacuum window and at the downstream side of which, the monitoring apparatus is disposed; and an irradiation management apparatus that controls irradiation of the charged particle beam, wherein a length of the low-scattering gas filling chamber is adjustable in such a manner that the monitoring apparatus is moveable in the beam-axis-direction relative to the vacuum window, and wherein when the charged particle beam is irradiated, the low-scattering gas filling chamber is filled with a low-scattering gas that scatters the charged particle beam less than air does.