PROBLEM TO BE SOLVED: To provide an apparatus for forming a magnetic field which forms a high magnetic field and a magnetic field distribution where acceleration is enabled up to an energy available for treatment of cancer or the like due to heavy particles although its size is small and its installation cost and operation cost are low, wherein a high magnetic field having a radial magnetic gradient for coping with an increase in mass for a relativistic effect due to an increase in energy is formed, and a variation in a circumferential magnetic field for beam (radiation) convergence is formed.SOLUTION: Two sets of coil groups or superconductive bulk body groups, in which a plurality of fan-shaped coils or fan-shaped oxide superconductive bulk bodies prepared by winding an oxide superconductive conductor are circumferentially arranged, are placed in a way that they face each other.COPYRIGHT: (C)2010,JPO&INPIT【課題】小型であり設置コストや運用コストが低廉でありながら、重粒子につきがん治療等に利用可能なエネルギーまで加速が可能となるような高磁場並びに磁場分布を形成することができ、エネルギーの増大に伴う相対論効果のための質量増加に対応するための径方向の磁気勾配を有する高磁場並びにビーム(放射線)収束のための周方向磁場の強弱を形成することができる磁場形成装置を提供する。【解決手段】酸化物超電導導体を巻いて成る扇形形状のコイル若しくは扇形形状の酸化物超電導バルク体が複数周方向に並べられたコイル群あるいは超電導バルク体群を、互いに向き合った状態で2組配置する。【選択図】図1
