PROBLEM TO BE SOLVED: To provide a technique for building a particle beam therapy system that can improve an availability rate by making an installation period shorter during which therapy is interrupted.SOLUTION: A particle beam therapy system 1 comprises: a circular accelerator 3 for accelerating charged particles； a beam transport line 4 for guiding the charged particles accelerated by the circular accelerator 3 to a projection chamber 18； a shielding wall 23 located around a radiation control area 16 in which the circular accelerator 3 and the beam transport line 4 are disposed, to shield radiation generated from the circular accelerator 3 and the beam transport line； a specific part 34 provided at a position separating the outside of the shielding wall 23 from the radiation control area 16 so that an additional opening for a projection chamber 19 can be formed； and a blocking part 35 for blocking the specific part 34 to shield radiation transmitted through the specific part 34.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2020,JPO&INPIT【課題】工事を行う際に治療が中断される期間を短くして稼働率を向上させることができる粒子線治療システムの構築技術を提供する。【解決手段】粒子線治療システム１は、荷電粒子を加速する円形加速器３と、円形加速器３で加速された荷電粒子を照射室１８に導くビーム輸送ラインと、円形加速器３およびビーム輸送ライン４が配置される放射線管理区域１６の周囲にあって、円形加速器３およびビーム輸送ライン４から生じる放射線を遮蔽する遮蔽壁２３と、遮蔽壁２３における外と放射線管理区域１６とを隔てる位置に設けられ、照射室１９の増設用開口部を形成可能な特定部３４と、特定部３４を閉塞し、この特定部３４を通過する放射線を遮蔽する閉塞部３５とを備える。【選択図】 図２
