Basic Imaging
Objective Stigmator Adjustment
See the TEM Alignment video in JEOL JEM-4000FX TEM.
NOTE: This technique assumes you are imaging carbon grid.
| 1. SPOT SIZE = 1, MAG = 100 kX. Spread the beam with the BRIGHTNESS knob. | VIEW | |||||
| 2. Depress the SCREEN button 2 times. | VIEW | |||||
3. Using the GATAN CAMERA, locate a feature on the grid. See the step Activate GATAN CAMERA under High Voltage Centering Adjustment in JEOL JEM-4000FX TEM. |
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4. Slowly increase the MAG to ~250 kX. |
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| 5. Adjust the OBJ FOCUS knob to focus the image. NOTE: This focus should occur near the voltage specified above for a particular accelerating voltage. If not, re-adjust the Z height slightly. |
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6. In the DigitalMicrograph program, select PROCESS > LIVE > FFT. |
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7. Adjust the OBJ FOCUS until an ellipse or circle appears in the FFT window, NOT a cross. |
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| 8. Depress the DEFLECTOR, OBJ STIG button on the left panel. | VIEW | |||||
| 9. Adjust the DEF X,Y (on main panel) until an ellipse becomes a circle. Ensure the X 10 button is on (button is lit). Use OBJ FOCUS to refocus the image. NOTE: Ideal contrast in the amorphous region should be matted (black and white dots – "salt and pepper") over or under focus, with no streaking or directionality. At exact focus very little contrast should be present. |
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| 10. Disengage the DEFLECTOR, OBJ STIG button. | VIEW | |||||
| 11. Disengage the screen by pressing the SCREEN button once. NOTE: This alignment changes with position on the specimen. NOTE: You may have to re-center the illumination using the SHIFT X,Y knobs (on main panel) when scanning the specimen. NOTE: HV centering, Z height, and objective lens stigmator settings vary from region to region in the specimen. |
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| 12. Click Stop View in the Camera View panel of the DigitalMicrograph software. Uncheck Camera Inserted. | VIEW | |||||
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