| 摘要 |
PROBLEM TO BE SOLVED: To prevent uniformity in an electron beam dosage distribution from being worsened in a divided direction in extraction electrodes by thermal expansion of the electrodes. SOLUTION: In this electron source 6a, mechanical connection is effectuated between the adjacent fellow extraction electrodes in the plurally divided electrodes 12a-12c, by connection means 30 allowing expansion and contraction in the divided direction Y of the electrodes, 12a-12c and precluding movement along a vertical direction Z.
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