| 摘要 |
PURPOSE:To irradiate the target with heavy ions having small deflection angle by applying a magnetic field to the ion accelerating region or ion extracting region in the primary ion source in order to deflect the light ions and by shielding them with slits. CONSTITUTION:A magnetic field generating means 5 consisting of plane permanent magnet in which the N and S poles are opposed to each other is provided between a lens electrode 2 and earth slit 3, in a high voltage ion source. The accelerated cluster ions sent from an ion generating part 1 are allowed to pass through the magnetic field generating means 5 in order to largely deflect the light ions 8'. The deflected light ions are eliminated by slit 3 and thereby only the heavy ions 8 are sent to the target 9. In this case, the lens electrode 2 and the magnetic field generating means 5 are integrated together and the structure can be formed compact through common use of the magnetic field generating means 6 having a pair of opposed poles as the lens electrode. Moreover, a large magnetic field intensity is no longer required in case the ions are deflected before they are sufficiently accelerated. |
