| 摘要 |
PURPOSE:In a macroanalyzer having an automatic beam matching mechanism, to automatically matching the position of the electron beam irradiated onto the required position of a specimen. CONSTITUTION:XY stage 25 is moved and the strength of the reflected electron from two kind of metals 26a, 26b is set to the reference voltage generator 31 through the variable resistors VR1 and VR2 then each LED lamps A, B will light/unlight to complete the setting. The output signal of 1/2(V1+V) from the voltage generator 31 is compared with the output signal from minute current amplifier 28 at the differential amplifier 30, then the output is fed to the electromagnetic axis matching power source circuit 27 to drive the electromagnetic axis matching coil 21 thus to deflect the electron beam. When driving the first and second switches 29, 32 and controlling untill there is no difference in X and Y direction the XY cross point of the specimen 26 is produced. With such structure and function, accurate matching of beam can be performed automatically without relying on CRT. |
