| 摘要 |
PURPOSE:To remove the effect of a field controller (FC) by arranging the 2-pole magnet in the 2-, 4-, and 6-pole magnets which constitute a static concergence magnet (STC-MAG) at the position separated farest from the field controller. CONSTITUTION:A 2-pole magnet is arranged at the position of the magnet 14 in the three sets of magnets 12, 13, and 14 which constitute a STC-MAG3. Since this permits the distance between the magnets 12 and 14 is about 20mm in general, the magnetic field of the 2-pole magnet is hardly distubed by the FC11 and 11'. The misconvergence of the central beam is also actually out of question. |
