| 摘要 |
PROBLEM TO BE SOLVED: To provide a method in which as for the voltage applied on an electrode constituting an extraction electrode system of an ion source, a voltage which is suitable for making small both deviation angle and divergence angle of ion beams can be determined in a short time and easily. SOLUTION: When the voltage to be applied on a first to a third electrodes 11-13 is V<SB>1</SB>-V<SB>3</SB>, V<SB>1</SB>-V<SB>2</SB>is a differential voltage V<SB>12</SB>, and V<SB>2</SB>-V<SB>3</SB>is a differential voltage V<SB>23</SB>, the voltage V<SB>1</SB>is established to a desired voltage. The action of obtaining a peak value and the differential voltage V<SB>12</SB>at that time by changing the differential voltage V<SB>12</SB>and measuring the beam current of the ion beams 20 extracted from the ion source is carried out by changing the differential voltage V<SB>23</SB>at every prescribed voltage in a prescribed range. By comparing the peak value and obtaining the differential voltage V<SB>12</SB>when the peak voltage becomes maximum, the obtained result is made V<SB>12p</SB>. The deviation angle of the ion beams 20 is measured by changing a combination of the voltage V<SB>2</SB>and the voltage V<SB>3</SB>without changing the voltage V<SB>1</SB>in a range to satisfy 0<V<SB>12</SB>≤V<SB>12p</SB>. Then, the combination of the voltage V<SB>2</SB>and the voltage V<SB>3</SB>in which the deviation angle becomes minimum is determined. COPYRIGHT: (C)2009,JPO&INPIT
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