Tecnai on-line help manual -- Alignments - UT Southwestern

<strong>Tecnai</strong> on-line help Alignments 64<strong>Tecnai</strong> 12 Software version 2ProcedureThe alignment procedure consists of two steps:• The first step is a preparation step to center and focus the beam on the viewing screen.• In the second step the beam is scanned so the scan frame is visible on the viewing screen. Changethe rotation correction setting until the scan line (the fast scan direction) goes from left to right (W toE) on the screen and the scan frame (the slow scan direction) goes from top to bottom.Note: The movement of the beam during scanning can be described as follows:• Move the beam to the starting position of the scan image (top left).• Move the beam along a line (the horizontal direction in the scan image).• At the end of the line, jump back to the beginning of the line (the flyback) and change the beamposition one line down.• Repeat this until you reach the bottom of the scan image at the end of the last line.• Go back to the first step.The horizontal direction in scanning is referred to as the 'line', while the vertical direction is called the'frame'. Since the frame is built up line by line, the scan in the direction of the frame is much slower thanthat along the lines.