| 摘要 |
A positive ion, which has been injected from an ion source into an ion acceleration device (16) and is flying inside an ion acceleration tube (24), is accelerated by a plurality of acceleration electrodes (2a to 2h) disposed inside the ion acceleration tube (24), and radiated onto a radiation target. A plurality of magnetic devices (5) are disposed inside the acceleration tube (24), and the orientation of each magnetic field line formed by each magnetic device (5) is set differently between adjacent magnetic devices (5) by an angle of greater than 0 degrees but no greater than 90 degrees, such that each magnetic field line is rotated in one direction inside the ion acceleration tube (24). An electron progressing in reverse inside the ion acceleration tube (24) is caused to intersect with a magnetic field line so that, as the electron progresses in reverse, the distance thereof to the flight axis increases. Since the electron collides with a member inside the ion acceleration tube (24) and is stopped before reaching a high energy, no high-energy X ray is generated. |
