/usr/lib/python2.7/dist-packages/PyMca/IncoherentScattering.py is in pymca 4.7.1+dfsg-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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# Copyright (C) 2004-2012 European Synchrotron Radiation Facility
#
# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
# the ESRF by the Software group.
#
# This file is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your option)
# any later version.
#
# This file is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
#############################################################################*/
__author__ = "V.A. Sole - ESRF Data Analysis"
import os
import numpy
from PyMca import ConfigDict
from PyMca import PyMcaDataDir
ElementList= ['H','He','Li','Be','B','C','N','O','F','Ne',
'Na','Mg','Al','Si','P','S','Cl','Ar','K','Ca','Sc','Ti','V','Cr','Mn','Fe','Co','Ni','Cu','Zn',
'Ga','Ge','As','Se','Br','Kr',
'Rb','Sr','Y','Zr','Nb','Mo','Tc','Ru','Rh','Pd','Ag','Cd',
'In','Sn','Sb','Te','I','Xe','Cs','Ba','La','Ce','Pr','Nd',
'Pm','Sm','Eu','Gd','Tb','Dy','Ho','Er','Tm','Yb','Lu','Hf',
'Ta','W','Re','Os','Ir','Pt','Au','Hg','Tl','Pb','Bi','Po','At',
'Rn','Fr','Ra','Ac','Th','Pa','U','Np','Pu','Am','Cm','Bk','Cf',
'Es','Fm','Md','No','Lr','Rf','Db','Sg','Bh','Hs','Mt']
dirmod = PyMcaDataDir.PYMCA_DATA_DIR
ffile = os.path.join(dirmod,"attdata")
ffile = os.path.join(ffile,"incoh.dict")
if not os.path.exists(ffile):
#freeze does bad things with the path ...
dirmod = os.path.dirname(dirmod)
ffile = os.path.join(dirmod, "attdata")
ffile = os.path.join(ffile, "incoh.dict")
if not os.path.exists(ffile):
if dirmod.lower().endswith(".zip"):
dirmod = os.path.dirname(dirmod)
ffile = os.path.join(dirmod,"attdata")
ffile = os.path.join(ffile, "incoh.dict")
if not os.path.exists(ffile):
print("Cannot find file ", ffile)
raise IOError("Cannot find file %s" % ffile)
COEFFICIENTS = ConfigDict.ConfigDict()
COEFFICIENTS.read(ffile)
xvalues = COEFFICIENTS['ISCADT']['XSVAL']
svalues = numpy.reshape(COEFFICIENTS['ISCADT']['SCATF'], (100, len(xvalues)))
#svalues = COEFFICIENTS['ISCADT']['SCATF']
#print svalues[100:110]
KEVTOANG = 12.39852000
R0 = 2.82E-13 #electron radius in cm
def getZ(ele):
if ele in ElementList:
return float(ElementList.index(ele)+1)
else:
return None
def getElementComptonFormFactor(ele, theta, energy):
return getElementIncoherentScatteringFunction(ele, theta, energy)
def getComptonScatteringEnergy(energy, theta):
return energy/(1.0 + \
(energy/511.) * (1 - numpy.cos(theta*(numpy.pi / 180.0))))
def getElementIncoherentScatteringFunction(ele, theta, energy):
"""
Usage:
getIncoherentScatteringFunction(ele,theta, energy):
ele - Element
theta - Scattering angle in degrees
energy- Photon Energy in keV
This routine calculates the incoherent scattering function
in electron units an interpolation to EGS4 tabulation of S(x,Z)/Z
"""
if ele in ElementList:
z = getZ(ele)
else:
z = float(ele)
wavelength = KEVTOANG / energy
sinhalftheta = numpy.sin(theta * (numpy.pi / 360.0))
#Hubbel just give this term
x = sinhalftheta / wavelength
#print "x old = ",x
e = energy/511.0
#Fajardo uses:
x = x * numpy.sqrt(1.0 + e* (e+2.0)* pow(sinhalftheta, 2))/ \
(1.0 + 2.0 * e * pow(sinhalftheta, 2))
#print "x new = ",x
ilow = 0
ihigh = 44
i = 22
while (ihigh - ilow) > 1:
if x < xvalues[i]:ihigh = i
else:ilow =i
i = int((ihigh+ilow)/2)
if z > 100:
if ihigh == ilow:
value = svalues[int(99),ilow]
else:
A = (x - xvalues[ilow])/(xvalues[ihigh]-xvalues[ilow])
value = ((1.0 - A ) * svalues[int(99),ilow] + \
A * svalues[int(99),ihigh])
value = value * (z/100.)
else:
if ihigh == ilow:
value = svalues[int(z-1),ilow]
else:
A = (x - xvalues[ilow])/(xvalues[ihigh]-xvalues[ilow])
value = ((1.0 - A ) * svalues[int(z-1),ilow] + \
A * svalues[int(z-1),ihigh])
return value
def getElementComptonDifferentialCrossSection(ele, theta, energy, p1=None):
if p1 is None:p1=0.0
if (p1 > 1.0) or (p1 < -1):
raise ValueError(\
"Invalid degree of linear polarization respect to the scattering plane")
thetasin2 = pow(numpy.sin(theta * numpy.pi / 180.0), 2)
thetacos = numpy.cos(theta * numpy.pi/180.0)
e = energy/(1.0 + (energy/511.) * (1.0 - thetacos))
return 0.5 * ((e/energy) + (energy/e) + (p1-1.0) * thetasin2) * \
pow(R0*(e/energy)*getElementIncoherentScatteringFunction(ele, theta, energy),2)
getElementIncoherentDifferentialCrossSection=\
getElementComptonDifferentialCrossSection
if __name__ == "__main__":
import sys
if len(sys.argv) > 3:
ele = sys.argv[1]
theta = float(sys.argv[2])
energy= float(sys.argv[3])
print(getElementComptonFormFactor(ele, theta, energy))
else:
print("Usage:")
print("python IncoherentScatteringFunction.py Element Theta(deg) Energy(kev)")
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