CtfExplorer Overview

CTF Explorer allows to calculate the Phase Contrast Transfer Function (CTF): a useful characteristics in Electron Microscopy 

Features

• Calculates 1-Dimensional CTF
  

• Calculates 2-Dimensional CTF
  

• Calculates Defocus Map
  

• Shows the effects of 2-Fold and 3-Fold astigmatism
  

• Allows to change Defocus, 2-Fold and 3-Fold astigmatism in real time
  

• Shows what happens to 1D CTF in different directions when there's astigmatism
  

• Displays the damping envelopes
  

• Select a microscope from a list of microscopes
  

• Create a custom microscope
  

• Change HT, Cs, Cc, Energy Spread, Convergence for any microscope
  

• 2 modes of operation: CTF Explorer (to see everything) and CTF Plotter
  

• Compare 2 microscopes or 2 settings for 1 microscope
  

• Save 1D CTF, 2D CTF and "Defocus Map" as bitmaps or metafiles

Added in 0.999a (10 February 2002)

• Corrected an error in the formula used for Focal Spread calculation which caused too strong damping by temporal envelope at high frequencies. Thanks to Michael O'Keefe, Peter Tiemeijer and Uwe Lucken for pinpointing this.
  

• Added a posibility to change number for High Tension and Objective Lens current instabilities (along with chromatic aberration and energy spread they affect the value of focal spread)
  

• Added a possibility of editing/saving/restoring of the microscope list

Added in 0.99b6 (5 December 2001)

• Euro-bug removed. When installed on a computer with a Windows locale which uses a comma instead of a point as a decimal separator, ctfExplorer would rise an exception. Now it's fixed but one needs to use a point '.' when editing a microscope. I.e. always write 1.3 instead of 1,3 etc.

Added in 0.99b5 (18 August 2001)

• User interface improvements and fixes
  

• Extended microscope list

Added in 0.99b4 (30 November 2000)

• "Magnification" slider control. Now it is possible to change convergence by adjusting the Magnification slider control (Higher magnification corresponds to less parallel beam). This is to show why it is not a good idea to do HRTEM at x1,000,000 magnification and why sometimes pictures taken at x200,000 look better than those taken at x500,000
  

• Export of ctfExplorer 1-D plots to tab-delimited text format
  

• "Lichte defocus" is included to the list of the most useful defoci

Credits

• ctfExplorer is written by Maxim V. Sidorov (maxthebuilder @ gmail.com)
  

• The following sources are quoted throughout this help manual (please refer to them if you want to know more about CTF and Theory of HR-TEM image formation):

1. D. B. Williams and C.B. Carter, Transmission Electron Microscopy: a textbook for material science, v. 3 Imaging, 1996 Plenum Press, New York

2. D. J. Smith, The Realization Of Atomic Resolution With The Electron Microscope, Rep. Prog. Phys. 60, (1997) 1513-1580

3. M. A. O'Keefe, "Resolution" In High-Resolution Electron Microscopy, Ultramicroscopy 47 (1992) 282-297

4. L. Reimer, Transmission Electron Microscopy (Physics of Image Formation and Microanalysis), 3rd Edition, Optical Sciences, 1993 Springer Verlag

© 2001, Maxim V. Sidorov

sidorov@yahoo.com
http://www.maxsidorov.com/ctfexplorer
http://clik.to/ctfexplorer