| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an air core type cyclotron that can form a magnetic field distribution such that the air core type cyclotron can be accelerated so as even to have energy enough to perform a cancer therapy per heavy particle even though the air core type cyclotron is small and has inexpensive installation cost and operation cost. <P>SOLUTION: A coil system 1 of the air core type cyclotron includes a pair of main coin units 2 for forming an isochronous magnetic field in a radial direction against an axial direction, and a pair of spiral sector coil units 4 for forming a magnetic field having strength and weakness in a circumferential direction. The spiral sector coil unit 4 includes a plurality of spiral sector coils 41. Each of the spiral sector coils 41 is an air core coil obtained by winding an oxide superconductor along a fan shape that is spirally curved, and is arranged so as to be rotational symmetry with respect to each other. <P>COPYRIGHT: (C)2012,JPO&INPIT |
