PROBLEM TO BE SOLVED: To provide a particle beam irradiation apparatus achieving a highly accurate beam irradiating position close to actualization based on actual data.SOLUTION: Each of X direction and Y direction inverse mapping mathematical expression models is a polynomial including both of two variables when displaying target irradiation position coordinates on the irradiation position plane of a charged particle beam by the two variables. An unknown coefficient included in the polynomial is obtained by the following processes: two or more sets of preset X direction and Y direction command values are inputted to X direction and Y direction scanning electromagnets to thereby control the charged particle beam and the actual data of respective actually irradiated irradiation position coordinates are subjected to a weighted least squares method for performing low weighting on some of the data.COPYRIGHT: (C)2011,JPO&INPIT【課題】実データに基づいたより実現実に近い高精度なビーム照射位置を実現できる粒子線照射装置が得られる【解決手段】X方向とY方向逆写像数式モデルは、それぞれ、荷電粒子ビームの照射位置平面における目標照射位置座標を2変数で表示したときの前記2変数のいずれも含んだ多項式であり、前記多項式に含まれる未知の係数は、前記X方向とY方向スキャニング電磁石に予め設定した複数組のX方向とY方向指令値を入力して、荷電粒子ビームを制御し、実際に照射されたそれぞれの照射位置座標の実データに対して、一部のデータに低い重み付けをする重み付け最小二乗法により求める。【選択図】図6
