| 摘要 |
<p>A magnetic system (34) for uniformly scanning ion beams comprising a magnetic structure (50) having poles (51) with scanning coils (58) and pole faces (52) that define therebetween a gap (54) through which the ion beam passes; and a magnetic circuit (60, 64) for producing in the gap (54) a magnetic field (56) of sufficient magnitude to prevent the occurrence of a recently observed plasma effect in which the transverse cross section of the ion beam substantially fluctuates in size while the ion beam is being scanned across the selected surface.</p> |
