| 摘要 |
PURPOSE:To eliminate error caused by fluctuation of beam during scanning in the measurement of beam diameter. CONSTITUTION:An electron beam 1 is deflected by a deflector 2 and scans on a knife edge 3. The beam is then detected through a Faraday cup 4 and amplified through an amplifier 6. A deflection control system 5 delivers a synchronizing signal to a signal operating section 7 where operation, e.g. scanning addition/averaging, is carried out and a beam diameter is displayed on a display system 8. A time axis coordinates point providing half level of the peak of detected waveform or a time axis coordinates point providing maximum first order differentiation values of reference waveform and detected waveform is set as an original point and the detected waveform or reference waveform and the difference therebetween are added and averaged.
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