Software Calibrations

• Connect to TEMCenter

1. CL2 >>Insert and center Aperture 2 >> Lift up the Screen >> Unclick Ronchigram >> Insert ADF1.
   Ensure the plastic cover of the fluorescence screen is put on so that lights are not allowed to enter as noises.

2. Adjust the Brightness and Contrast:
   The brightness should be very close to zero, adjust the Contrast to an acceptance range (bell-shaped histogram to the left side).
   Requirement: Both background (noises) and gold nanoparticles should be present on the ADF1 for Tableau calculation. If the brightness and contrast are still not optimized, one may choose to adjust the Detector Amp.

3. Use the Selector to zoom in (~ 5MX) and click the "Area" Tab.

4. Shift the image in x-direction using the hardware button to verify if stage orientation is aligned to the software.
   Requirement: Ensure the image move horizontally so that the software recognized which direction to tilt.
   Trick: If the image is not moving horizontally, one needs to tilt the image slightly via software.

5. Adjust the focus knob slightly so that the lattice fringe can be observed at ~ 10MX Magnification.

6. Reset to 1MX Magnification using the Selector.

• C1A1

1. Start the software correction by clicking the "C1A1" tab.

2. Correct C1 by using hardware by pressing "Z up" or "Z down" slowly.
   Correct A1 by using the software by pressing "A1" with the strength "75%".
   Correct WD by using the software by pressing "WD" with the strength "75%".
   Requirement: C1 and A1 should be less than absolute 10 nm; WD should be less than 1m rad.
   For the C1 correction, the UF and OF should be roughly the same in size. Go back to Ronchigram if C1, A1, and WD cannot be corrected after many trials.

3. Click "Stop" in C1A1 after the 3 values fall within the ranges.

• Tableau: Fast Mode

1. Go to the "Tableau" for calculation. Click the "Fast" tab >> Accept Aberrations >> StateOfCorrection
   The Fast Tableau mode is reliable until C3 - "C1, A1, A2, B2, C3".
   Requirement: C1 and A1 are less than absolute 10 nm; A2 and B2 are less than absolute 100 nm, C3 is less than 1um.
   We should correct aberration sequentially according to "C1, A1, A2, B2, C3" unless the C3 is very severe (e.g., 5 um).
   At any point in time, we should only correct 1 aberration.
   After C3 correction, we should examine if there is any A1 and B2 using Ronchigram. This is because the higher-order aberration tends to induce lower-order aberrations considerably.

2. After Ronchigram correction, if any (due to C3 or others), go back to the "C1A1" tab.

3. Perform the Tableau correction thereafter in Fast Mode iteratively (Ronchigram --> C1A1) until everything falls within the ranges.

• Tableau: Standard Mode

1. Go to the "Tableau" for calculation. Click the "Standard" tab >> Accept Aberrations >> StateOfCorrection
   The Standard Tableau mode is more reliable (as more points are used for calculation) until B4 - "C1, A1, A2, B2, C3, A3, S3, A4, D4, B4".
   C5 and higher-order aberrations cannot be corrected by the software.
   Requirement: A3 and S3 are less than 1um; A4, D4, and B4 are less than 3 um.
   Trick: We should correct aberration sequentially according to "C1, A1, A2, B2, C3, A3, S3, A4, D4, B4" unless the S3 or the latter is very severe (e.g., 8um). At any point in time, we should only correct 1 aberration.
   After S3 correction, we should examine if there is any A1 and B2 using Ronchigram. This is because the higher-order aberration tends to induce lower-order aberrations considerably.

2. After Ronchigram correction, if any (due to C3 or others), go back to the "C1A1" tab.

3. Perform the Tableau correction in Standard Mode iteratively (Ronchigram --> C1A1 --> Fast Mode) until everything falls within the ranges.

• Go back to Ronchigram and check if we obtain a large featureless (blown-up) and flat region.
  Trick: Ronchigram is our final judgment of the quality calibrations before proceeding to high-resolution imaging.

Important Notes
You should only correct the higher-order aberrations very subtly as they create SEVERE lower-ordered lens aberrations.