Version History

Example of how to reference this online database:

Berger, M.J., Hubbell, J.H., Seltzer, S.M., Chang, J., Coursey, J.S., Sukumar, R., Zucker, D.S., and Olsen, K. (2010), XCOM: Photon Cross Section Database (version 1.5). [Online] Available: http://physics.nist.gov/xcom [2025, March 13]. National Institute of Standards and Technology, Gaithersburg, MD.
Optional addition:
Originally published as Berger, M.J. and Hubbell, J.H., "XCOM: Photon Cross Sections on a Personal Computer," NBSIR 87-3597, National Bureau of Standards (former name of NIST), Gaithersburg, MD (1987); and as Berger, M.J. and Hubbell, J.H., "NIST X-ray and Gamma-ray Attenuation Coefficients and Cross Sections Database," NIST Standard Reference Database 8, Version 2.0, National Institute of Standards and Technology, Gaithersburg, MD (1990).

Citation Form:

Author/editor (Year), Title (edition). [Type of medium] Available: URL [Access date].

Version 1.5 November 2010	The number of significant figures reported was increased from three to four; the 4th significant figure is not intended to indicated accuracy but to aid interpolation. The web version is now based on the downloadable version (3.1) of XCOM. Other minor changes were made.
Version 1.4 February 2009	Inconsistencies in tabular data were corrected.
Version 1.3 August 2005	Improvements were made to the graphing procedure.
Version 1.2 August 1999	XCOM version 3.1 FORTRAN-77 source code and executables made available for downloading.
Version 1.1.3 May 1999	Additional energies limited to 75 to ensure accurate data.
Version 1.1.2 April 1999	Users were advised to use no more than 70 additional energies.
Version 1.1.1 October 1998	Correction made to properly deal with very small components of mixtures.
Version 1.1 July 1998	New user interface, extended graphing capabilities, and text modifications to reflect these changes.
Version 1.0 March 1998	NIST Standard Reference Database 8 (XGAM) (only the web version is available as of September 28, 1998) "NIST X-Ray and Gamma-Ray Attenuation Coefficients and Cross Sections Database," Distributed by the NIST Standard Reference Data Program Version 2.0: June 1990 Version 1.0: April 1987
Earlier Publication July 1987	"XCOM: Photon Cross Sections on a Personal Computer," NBSIR 87-3597, M.J. Berger and J.H. Hubbell, National Bureau of Standards (former name of NIST), Gaithersburg, MD.