Apreo SEM Startup - BYU Electron Microscopy Facility Skip to main content
Electron Microscopy Facility
Subsidiary of the Research and Graduate Studies Office of the AVP

Apreo SEM Startup

By Michael Standing,
May 05, 2023 01:56 PM

Basic Operating Instructions for the Apreo SEM (105 MB)

  1. Getting Started

    1. Door Code:  Proximity Card Reader (unlocked during business hours)
    2. Microscope should be logged in and the software up and running.  If there is an error message or if it is not then contact Mike to correct the problem and/or train you to do this.
    3. Check the vacuum status (column icon on bottom of the screen should be all green) and the gun emission (green bar under the BEAM ON button).  If either of these are not green then contact Mike

  2. Loading and Positioning the Sample

    1. Open the chamber

      1. Press the vent button and confirm the vent
      2. Note that if the chamber fails to vent after several minutes (watch the green progress bar on the bottom of the screen) then contact Mike to change the N2 gas cylinder.
    2. NOTE:  It is important to keep the specimen chamber as clean as possible.  Please wear powder free nitrile gloves when directly handling microscope parts or samples.  Gloves are available in rooms 106 and 109 (dry lab and wet lab).

    3. Put sample on sample holder

      1. Specimens need to first be mounted to an appropriate specimen mount.  See Mike if you have questions about how to do this.  We will call this the sample.

      2. Place the sample(s) into the appropriate position(s) on the sample holder in the microscope.  

        1. Please note that all of the samples being placed in the microscope need to be approximately the same height (within 1-2 mm).
        2. Sample positions are secured by either a set screw (positions labeled with the word screw next to them) or by a spring.  Unless you are using a particularly massive sample and you are tilting the stage then the positions secured with a spring are prefered.  Make sure when you are using either type of securing mechanism that the sample mount is pushed securely down into the hole.

    4. ENSURE THE SAMPLE WILL NOT HIT THE POLE PIECE

      1. Make sure the CCD image is not paused

      2. Slowly close the door and carefully watch that your sample stays below the 10mm marker on the image.

        1. If the top of the highest sample appears to be above the 10 mm marker on the image, open the door and lower the stage.

          1. Select the navigation panel
          2. Adjust the Z value to a lower number until you are sure the top of the sample will not be above the 10 mm marker.
          3. A value of 0 is all the way down.  If your sample still appears to be above the 10 mm marker then your sample is too tall for the microscope and must be adjusted in some way to correct this.  If you have questions see Mike.
    5. If desired, select the “take nav-cam photo” box to take a new nav-cam photo.  This can be done afterward if necessary.
    6. Press the Pump button and then select the “No Accessory” item from the pop-up window unless you have installed one of the two available accessories.
    7. Click in the upper left quadrant to activate it

    8. While the chamber is pumping select the following parameters (NOTE:  These parameters will provide a basic starting condition so you should get an image to start with.  You may start with other conditions depending on your particular project):

      1. KV: 5KV
      2. Probe current: 0.10 nA
      3. Use Case: Standard
      4. Detector: ETD
      5. Dwell time: 100 ns
      6. Image resolution: 1536 X 1024
      7. Select the area on a sample you want to start with by double clicking on the area of interest on the nav-cam photo
    9. When the chamber has been pumped to an adequate vacuum, the BEAM ON button will become available and the column icon on the bottom of the screen will be green again.  Turn on the HT by clicking on the BEAM ON button.
    10. Unpause the image by clicking on the green pause button on the upper left quadrant.
    11. If the image is too bright or dark then press the auto contrast button or adjust the brightness and/or contrast knobs on the controller.

    12. Focus the image using the focusing knobs on the controller and link the Z to FWD (Z<=>FWD)

      1. Find a reasonable focus at low magnification first

        1. If you find you can’t really see the focused image very well do the following:

          1. Check the WD on the image
          2. Look at where the top of the sample is in relation to the 10 mm marker.
          3. Estimate the total distance your sample is most likely away from the pole piece
          4. Adjust the WD on the image using the focusing knobs until it is close to what you estimate the distance the sample is from the pole piece.
      2. Once a reasonable focus has been obtained, increase magnification to over 1,000X and refocus until you are reasonably well focused.
      3. Link the Z to FWD
      4. Bring the sample up to 10 mm using the Z axis control.
      5. Re focus the image and re link the Z to FWD.
      6. You are now ready to start your imaging session.

  3. Unloading the sample and ending your microscope session

    1. Pause the active images (optional)
    2. Press the VENT button and confirm the vent.
    3. Remove sample(s) after the vent process has completed
    4. Adjust the stage to 47 mm using the Z axis control.

    5. Pump the chamber back to high vacuum

      1. Press the Pump button and then select the “No Accessory” item from the pop-up window unless you have installed one of the two available accessories.