Xray::Absorption::McMaster(3pm) 			User Contributed Perl Documentation			   Xray::Absorption::McMaster(3pm)

       "cross_section"
	   Example:

	      $xsec = Xray::Absorption -> cross_section($elem, $energy, $mode);

	      @xsec = Xray::Absorption -> cross_section($elem, @energy, $mode);

	   The $mode argument is different here than for the other resources.  The options are "xsec", "photo", "coherent" and "incoherent",
	   telling this method to return the full cross-section or just the photoelectric, coherent, or incoherent portions.

	   The values for all cross-sections are computed as log-log polynomials as described in the original paper by McMaster et al.

NAME

       Xray::Absorption::McMaster - Perl interface to the McMaster tables

SYNOPSIS

	  use Xray::Absorption;
	  Xray::Absorption -> load("mcmaster");

       See the documentation for Xray::Absorption for details.

DESCRIPTION

       This module is inherited by the Xray::Absorption module and provides access to the data contained in the 1969 McMaster tables.

       The data in this module, commonly referred to as "The McMaster Tables", was originally published as

	 Compilation of X-Ray Cross Sections
	 W.H. McMster, N. Kerr Del Grande, J.H. Mallett, J.H. Hubbell
	 National Bureau of Standards
	 UCRL-50174 Section II Revision 1(1969)
	 Available from National Technical Information Services L-3
	 United States Department of Commerce

       This can be a bit difficult to find.  IIT's Galvin library has kindly made a scan of it available:
       http://www.gl.iit.edu/govdocs/resources/xray.html

       The data is contained in a database file called mcmaster.db which is generated at install time from a flat text database of the McMster
       data.  The data originally comes from mucal.f, a Fortran subroutine originally written by Dr. Pathikrit Bandhyapodhyay.

       The required Chemistry::Elements module is available from CPAN in the miscellaneous modules section.

EDGE AND LINE ENERGIES

       The McMaster data resource only includes K and L 1-3 edges.  For light elements, it provides only a single L edge energy -- that for the L1
       edge.  For heavier elements it provides a single M energy, the energy of the M1 edge.  It only supplies four generic fluorescence line
       energies, Kalpha, Kbeta, Lalpha, and Lbeta.  In each case the energy provided is the energy of the brightest line of that sort.

BUGS AND THINGS TO DO

       o   Make sure this handles fluorescence lines which are in other resources, but not in this resource in a sensible manner.

       o   What happens if you call "line_toggle" when this is loaded?	How about when elam was loaded but then you switch to this one?

AUTHOR

	 Bruce Ravel, bruce@phys.washington.edu
	 http://feff.phys.washington.edu/~ravel/software/Absorption/

perl v5.12.4							    2011-07-30					   Xray::Absorption::McMaster(3pm)