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Apex a22, showing a 1D cylinder composition profile
Maintainer Olof Hellman
Latest release: alpha-41 / May 31, 2006
OS: Mac OS X
Genre: Atom-Probe Tomographic Analysis
License: By arrangement with Olof Hellman
Website: http://www.tomographic.com/

Apex (Atom-probe experience) is a Macintosh OS X program developed by former Seidman-group member Olof Hellman under his company "Tomographic Softworks [1]." Apex runs on all of the NUCAPT macs and some of the personal machines of individuals in the Seidman group. Please contact Olof directly if you'd like to use Apex on your non-NU computer.

System Requirements

A mac with a G4 or G5 processor and OS X 10.3.9 or later is recommended. Apex can run on OS 10.3.8 and earlier versions of 10.3, but you will need to install libstdc++ version 6.0. However, the easiest way of doing this is to upgrade (for free) to version 10.3.9. The more memory the better, but at least 512 MB is recommended. In addition, one should have sufficient free disk space. As a rule of thumb, at least 100 bytes of free disk space per ion in a dataset you wish to work on – If you have a dataset of 2 million ions, try to have 200MB of free disk space. NUCAPT has a dual-2.7 GHz G5 with 8 GB of RAM and plenty of disk space to run Apex.


  • Adjustable isoconcetration surfaces[2]
  • Proxigram[3][4]
  • Imports:
    • .pos (standard for many atom-probe groups)
    • .ops (used by the Oxford group)
    • .dat files (used by the Rouen group)
    • .atomlist files (originally used by the Northwestern group with the 3DAP)
  • Exports:
    • .pos
    • .atomlist
    • .ato (wide data / Rouen format)
  • Manipulation via
    • GUI
    • Applescript


The calculation of the Gibbsian interfacial excess is described in:

Hellman, Olof C.; Seidman, David N. (2002). "Measurement of the Gibbsian interfacial excess of solute at an interface of arbitrary geometry using three-dimensional atom probe microscopy". Materials Science and Engineering A 327 (1): 24-28. doi:10.1016/S0921-5093(01)01885-8.