| 摘要 |
PURPOSE:To equalize intervals to respective electrode shields and to hold the intervals over the entire area of respective electrodes even if an external force is applied by forming a film of a conductive material on the wall surface of a cylindrical insulator by vapor deposition. CONSTITUTION:This monitor consists of electrodes 11 (4a and 4b) arranged in a peripheral direction while surrounding the travel path of a charged particle beam 6 and shields 3a and 3b surrounding them from outside in common and the position of the beam 6 is detected from charges or the voltage to the shields. At this time, those electrodes 11 and shield 3b are formed by vapor-depositing a conductive material on the internal and external wall surfaces of a common cylindrical insulator 10. Thus, the interval between the electrodes 11 and shields 3 which is the largest factor of the output voltage of variance of the electrodes 11 is determined by the thickness of the insulator 10 and the individual difference of the output voltages of the electrodes becomes small. Those are formed in one body and never shift in relative position even if an external force is applied.
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