Mass Absorption Coefficients

EPMA Probe

Mass Absorption Coefficients

Probe for EPMA provides seven automatic lookup tables of mass absorption coefficients for use in the analytical calculations. \

LINEMU.DAT is a compilation of Henke (unpublished, 1985) coefficients for energies less than 10 keV and Heinrich (1966) for energies greater than 10 keV.

 

CITZMU.DAT is the complete set of coefficients from Heinrich used by John Armstrong at CalTech/NIST which is from Heinrich (1966) and Henke and Ebisu for the light elements.

 

MCMASTER.DAT is a calculated set derived from equations (fits) from McMaster at Livermore National Laboratory (modified by Rivers).

 

MAC30.DAT is from Heinrich (1987), which is a fit to the Goldstein, et. al. MAC table.

MACJTA.DAT is from Armstrong's MACCALC program.

 

FFAST.DAT is a tabulation of the Chantler (et. Al.) 2005 MAC values provided by Nicholas Ritchie (NIST 2005). The original published NIST table is at: http://physics.nist.gov/PhysRefData/FFast/Text/cover.html

 

See: Chantler, C.T., Olsen, K., Dragoset, R.A., Kishore, A.R., Kotochigova, S.A., and Zucker, D.S. (2005), X-Ray Form Factor, Attenuation and Scattering Tables (version 2.1). [Online] Available: http://physics.nist.gov/ffast [Mar-2005]. National Institute of Standards and Technology, Gaithersburg, MD. Originally published as Chantler, C.T., J. Phys. Chem. Ref. Data 29(4), 597-1048 (2000); and Chantler, C.T., J. Phys. Chem. Ref. Data 24, 71-643 (1995).

 

USERMAC.DAT is a user defined table of mass absorption coefficients from any number of sources. It is not distributed by Probe Software but can be created by the user based on an existing selected MAC table and edited as desired.

 

To obtain mass absorption coefficients for elements 93 and above, the USERMAC.DAT file should be created using the MAC30.DAT file as its “basis” and then updated using the USERMAC.TXT file from CalcZAF. The USERMAC.TXT file contains the database values from the Institute of Transuranium Elements. The reference is:

 

I. R. Farthing and C. T. Walker, Heinrich's Mass Absorption Coefficients for the K, L and M Lines, The European Commission, Institute for Transuranium Elements, Karlsruhe, Report K0290140,

1990

 

The default mass absorption coefficient file is LINEMU.DAT. This default MAC file may be specified in the PROBEWIN.INI file. If one or more of the mass absorption coefficients in these tables are not acceptable, the user can select the use of other empirically derived values from the Analytical | Empirical MACs menu. Empirical mass absorption coefficients will override values specified from the MAC tables.