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X-Ray Mass Attenuation Coefficients

NIST Standard Reference Database 126

Last Update to Data Content: July 2004 | NISTIR 5632 | Version HistoryDisclaimer | DOI:

Tables of X-Ray Mass Attenuation Coefficients and Mass Energy-Absorption Coefficients from 1 keV to 20 MeV for Elements Z = 1 to 92 and 48 Additional Substances of Dosimetric Interest*

J. H. Hubbell+ and s.seltzer [at] (S. M. Seltzer)
Radiation Physics Division, PML, NIST

© 1989, 1990, 1996 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. NIST reserves the right to charge for these data in the future.


Tables and graphs of the photon mass attenuation coefficient μ/ρ and the mass energy-absorption coefficient μen/ρ are presented for all of the elements Z = 1 to 92, and for 48 compounds and mixtures of radiological interest. The tables cover energies of the photon (x-ray, gamma ray, bremsstrahlung) from 1 keV to 20 MeV. The μ/ρ values are taken from the current photon interaction database at the National Institute of Standards and Technology, and the μen/ρ values are based on the new calculations by Seltzer described in Radiation Research 136, 147 (1993). These tables of μ/ρ and μen/ρ replace and extend the tables given by Hubbell in the International Journal of Applied Radiation and Isotopes 33, 1269 (1982).

Note on NIST X-ray Attenuation Databases

Table of Contents

  1. Introduction
  2. X-Ray Mass Attenuation Coefficients
    Table 1. Material constants for elemental media.
    Table 2. Material constants and composition for compounds and mixtures.
    Values of the mass attenuation coefficient and the mass energy-absorption coefficient as a function of photon energy, for:
    Table 3. [Data] elemental media.
    Table 4. [Data] compounds and mixtures.
  3. The Mass Energy-Absorption Coefficient
  4. Summary
  5. References

*Work supported by the Standard Reference Data Program of NIST.
+Work carried out for NIST under contract 43NANB412756.

NIST Standard Reference Database 126 | Customer Support | Online: May 1996  | Last update: July 2004


Created September 17, 2009, Updated February 17, 2022