Filter
Top Products
3.4 Adjusting the Electron Optical System
3 - 26
(4) Aperture Alignment
The Aperture Alignment is designed so that the electron beam will pass through the center
of the objective lens. If this alignment is not performed precisely, focusing operations can
shift the image, resulting in inadequate resolution or image quality.
Fig. 3.4-8 Aperture Alignment Menu
NOTICE: For normal observation, axial alignments should be performed using the
Electromagnetic Alignment. If the objective lens movable aperture is moved, reset
the aperture alignment to a mid-point. After that, use the objective lens movable
aperture to make adjustments so that the brightness of the image will be at a
maximum. In subsequent normal observations, axial alignments should be performed
using the Electromagnetic Alignment.
(A) Basic axial alignment by viewing an image
• Set the magnification factor from 1,000x to 5,000x. Move a spot on the specimen to
near the center of the image.
• Perform focus and stigmation adjustments.
• On the [Alignment] window, click the [Aperture Align] button to bring up the Aperture
Alignment mode in which the focus and the image position fluctuate periodically.
• Using either the STIGMA/ALIGNMENT knob on the Manual Operation Knobset or
the alignment operation area in the Alignment window, move the mouse while
holding down the left button of the mouse, and move the crosshairs so that the
motion of the image is minimized.
• Increase the magnification factor to 5000x or higher to perform final Aperture
alignments.
• After the adjustment process is finished, click the Off button on the Alignment
window.