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

<strong>Tecnai</strong> on-line help Options 18Options Software version 2Spot wobbleTo determine what the distances between the spot should be, click on Spot wobble. The spot will now bewobbled back and forth and the scroller can be adjusted until the spot just touch each other. The spotdistance is indicated above the spot slider (in arbitrary units when not calibrated, otherwise inmicrometers). The number of spots in the total scan is also indicated.Note: The optimum beam deflection range (reset when spotscan setup functions are switched on)affects the spot distance. Therefore always check the spot distance after setting the scan range.PreviewThe result of the spotscan setup can be viewed on the viewing screen to check that everything is alrightfor the exposure. This function is available only in the Low Dose Exposure state (press the Exposurebutton). The progress of the scan is indicated by the progress bar in the top of the panel (blueincreasingly fills the bar).ViewPressing the View button starts and stops the spot scan.SlowerWhen the Slower button is pressed, the spot dwell time is increased by a factor 2.FasterWhen the Faster button is pressed, the spot dwell time is reduced by a factor 2.To 0,0When the button To 0,0 is pressed, the scan is stopped and the beam is moved to the 0,0 position(center of the scan frame). If the beam is not centered on the screen, it should be shifted to the centerwith the normal beam shift (or Align beam shift alignment). The control of the AC beam deflection coils(used by spotscan) remains on.Shift awayWhen the Shift away button is pressed, the beam will be moved to an extreme X,Y position. It should notbe visible on the screen now (unless the magnification has been lowered from the exposuremagnification used during the setup). The control of the AC beam deflection coils (used by spotscan)remains on.AC offTo switch the AC coils (used by spotscan) control off after the preview, press the AC off button.