Take a sneak peek at the new NIST.gov and let us know what you think!
(Please note: some content may not be complete on the beta site.).

View the beta site
NIST logo

Standard Reference Data, NIST:
100 Bureau Drive, Stop 8550
Gaithersburg, MD 20899-8550
Tel: 301-975-2200
Fax: 301-975-4553

If you have any questions regarding this website, or notice any problems or inaccurate information, please contact the webmaster by sending e-mail to: data@nist.gov

Bookmark and Share

NIST Standard Reference Database 100

NIST Database for the Simulation of Electron Spectra for Surface Analysis (SESSA): Version 2.0


Price: $900.00 online

Mac Version online 

Linux Versiononline 

Discounted prices apply to multiple purchases of SESSA by the same organization; for information click here.

Rate our Products and Services

If you are having problems with the Online Purchase or Fax/Mail Order Link.

Effective immediately, there will be a minimum $30.00 shipping charge for all international shipments of databases via UPS International. Customer will be responsible for their own duties, tax, and VAT. Contact 301 975 2200 or data@nist.gov if you have questions.

Version 2.0 of SESSA can be used to simulate AES and XPS spectra of nanostructures such as islands, lines, spheres, and layered spheres on surfaces. As for earlier versions, such simulations can be performed for multilayer films. Users can specify the compositions and dimensions of each material in the sample structure as well as the measurement configuration, and the simulated spectra can be compared with measured spectra. Compositions and dimensions can then be adjusted to find maximum consistency between simulated and measured spectra.

This database has been designed to facilitate quantitative interpretation of AES and XPS spectra and to improve the accuracy of quantitation in routine analysis [1-3]. SESSA contains physical data needed to perform quantitative interpretation of an AES or XPS spectrum for a specimen of given composition and morphology (differential inverse inelastic mean free paths, total inelastic mean free paths, differential elastic-scattering cross sections, total elastic-scattering cross sections, transport cross sections, photoionization cross sections, photoionization asymmetry parameters, electron-impact ionization cross sections, photoelectron lineshapes, Auger-electron lineshapes, fluorescence yields, and Auger-electron backscattering factors). Retrieval of relevant data is performed by a small expert system that queries the comprehensive databases. A simulation module provides an estimate of peak intensities as well as the peak spectra.

The design of the software allows the user to enter the required information in a reasonably simple way. The modular structure of the user interface closely matches that of the usual control units on a real instrument. Any user who is familiar with a typical AES or XPS spectrometer can perform a retrieval/simulation operation with the SESSA software in a few minutes for a specimen with a given composition and morphology. A command line interface can also control the software; this feature allows users to load sequences of commands that facilitate simulations for similar conditions.

Version 1.0 of this database was released in December, 2005. Version 1.1 was released in December, 2006 with an enhancement to the Model Calculation screen that permits the user to display and save the zero-order partial intensities. Previously, a user had to go to another screen to perform these operations. Version 1.2 was released in March,2010 with the following enhancements: an additional and more intuitive format for specifying the composition of a material; a new capability to perform simulations with polarized photons; the ability to save plots in additional file formats; the addition of a chemical-shift database for selected peaks; improvements in the peak-management software; and incorporation of a faster random number generator. In addition, an internet SESSA forum has been established for user questions and a new SESSA bug-tracking web page has been established. Version 1.3 was released in May, 2011 with a new database of non-dipole photoionization cross sections that are necessary in simulations of X-ray photoelectron intensities with X-ray energies higher than a few keV. In addition, a description is given of how SESSA can be called and controlled from an external application. Version 2.0 was released in October, 2014 with additional capabilities for specifying specimen nanomorphologies (such as islands, lines, spheres, and layered spheres on surfaces) and with updated data for electron inelastic mean free paths.

A fully functional demonstration version of SESSA can be downloaded by clicking here. This trial version can be used for a 15-day trial period without charge.

Please click to view the PDF version of Users' Guide,

Systems Requirements:

SESSA runs on personal computers using the Windows operating system including Windows 7 32-bit and 64-bitsystems. The databases and software require a hard disc space of approximately180 MB. The minimum amount of RAM needed to run SESSA is about 15 MB, but 30 MB or more is needed for simulations. SESSA is also available for MacIntosh OS X and Linux operating systems, but these versions have not been as extensively tested as the Windows version, and are not supported.

If you are having problems with the Online Purchase or Fax/Mail Order Link.

Effective immediately, there will be a minimum $30.00 shipping charge for all international shipments of databases via UPS International. Customer will be responsible for their own duties, tax, and VAT. Contact 301 975 2200 or data@nist.gov if you have questions.

For more information please contact:

Standard Reference Data Program
National Institute of Standards and Technology
100 Bureau Dr., Stop 8550
Gaithersburg, MD 20899-8550
(301) 975-2200 (VOICE) / (301) 975-4553 (FAX) Contact Us (E-MAIL)


The scientific contact for the database is:

Cedric Powell
National Institute of Standard and Technology
Surface and Microanalysis Science
Division (837) phone: (301) 975-2534 email: cedric.powell@nist.gov


Additional information for users of SESSA is available at http://eaps4.iap.tuwien.ac.at/~werner/sessa.html.

1. W. Smekal, W. S. M. Werner, and C. J. Powell, Surf. Interface Anal. 37, 1059 (2005).2. W. S. M. Werner, Surf. Interface Anal. 31, 141 (2001).3. W. S. M. Werner, in Surface Analysis by Auger and X-ray Photoelectron Spectroscopy, D. Briggs and J. T. Grant, eds. (IMPublications, Chichester, 2003), p. 235.

Keywords: Auger-electron backscattering factors, Auger-electron lineshapes, Auger electron spectroscopy, cross sections, elastic scattering, electron-impact ionization cross section, electron scattering, electron transport, fluorescence yields, inelastic mean free paths, inelastic scattering, photoelectron lineshapes, photoionization asymmetry parameters, photoionization cross sections, surface analysis, transport cross sections, x-ray photoelectron spectroscopy.