Basic TEM alignment

Owned by gys37319
Last updated: Nov 26, 2021 by eha56862
Do not attempt to do anything you have not been trained to do by ePSIC staff.


  1. At the start of the day perform a high flash and run up the emission.
  2. Open the beam valve and check there is a beam on the large phosphor screen. Centre with beam shift.
  3. Insert and centre the largest condenser lens aperture (150μm)
  4. Ensure the objective lens is at standard focus and bring the sample to Gaussian focus height.
  5. Select the alpha value which you want to use.
  6. Select the spot size you with to use.
  7. Adjust any 2-fold astigmatism in the beam using condenser lens stig.
  8. Anode wobble and adjust beam deflectors (GunA2) until concentric movement is achieved.
  9. Go to 1 Mx magnification, find a feature on the sample and wobble the HT. Correct for any movement in the sample with beam align deflectors (CLA2).
  10. Correct for tilt balance using the tilt wobbler.
  11. Iterate steps 7-10 if necessary.
  12. At 1 Mx magnification illuminate a region of amorphous material, spread the beam, insert the One-View camera and lift the viewing screen.
  13. View a live FFT of the image and adjust two fold astigmatism using the corrector optics panel (make sure the toggle button is on TEM).
  14. If necessary run the COSMO corrector.
  15. Insert the required condenser lens aperture for imaging.


If you leave the microscope please ensure the beam valve is closed.

If you leave the microscope for an extended period of time:

  • Close the beam valve.
  • Run down the emission.

On returning to the microscope:

  • Perform a low flash.
  • Run the emission back up.

If your emission current drops significantly during your session you can restore to 15μA by following the above procedure.

Do not attempt to flash the tip while the emission is on.