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Update Controls

poghosyan_e
2024-11-29 15:12:59 +01:00
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Controls.md

@ -4,23 +4,23 @@ List of controls consists of all parameters needed for proper dataset acquisitio
##### Electron beam settings
- **Energy** energy of primary electron beam in keV
- **Probe** probe setting together with chosen probe forming aperture give probe
- **Probe** probe setting together with chosen probe forming aperture giving the probe
current (in two condenser lens system)
- **Defocus** moves focus out of the sample plane - enlarges beam diameter
- **Aperture** probe forming aperture gives probe semi-angle (α)
##### Scanning parameters
- **Magnification** controls image field of view
- **Matrix** gives beam position to position distance + beam defocus = beam overlap
- **Dwell time** single position beam time
- **Dwell time** a time for an electron beam to stay per pixel
##### Detection
- **Nominal CL** sample to detector distance (usually ADF) gives maximal detected angle as well as angular sampling
- **Detector** detector used for data collection
- **Use PAAR** Pumping Aperture Angular Restriction, build-in aperture may limit maximal scattering angles for shortest camera lengths
- **Binning** reduction in pixel array size usually increases maximum frame rate
- **Use PAAR** Pumping Aperture Angular Restriction, in some microscopes, differential pumping aperture which can limit maximal scattering angles for shortest camera lengths
- **Binning** reduction in pixel array size usually increases maximum frame rate (when available)
##### CL guide - build in checks for proper camera length selections for iterative reconstruction
- Low angle approximation - scattering angle < 10deg (unequally sampled pixel around optical axis and around detector edge)
- Low angle approximation - scattering angle < 10deg (unequally sampled pixel around optical axis versus around detector edge)
- Ptycho pixel < step size - set step size is smaller than final pixel in reconstructed image - loose of resolution
- Beam fits in probe window - probe window is capable to accommodate for defocused probe
- Beam fits inside the probe window - probe window is capable to accommodate for defocused probe
- Detector cover < 1α - no reconstruction method for such a dataset
- Detector cover > 6α - usually no scattering beyond 5α