TestEm7/src/G4LindhardPartition.cc

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0026 /*
0027  *  \file electromagnetic/TestEm7/src/G4LindhardPartition.cc
0028  *  \brief Implementation of the G4LindhardPartition class
0029  *
0030  *  Created by Marcus Mendenhall on 1/14/08.
0031  *  2008 Vanderbilt University, Nashville, TN, USA.
0032  *
0033  */
0034
0035 //
0036
0037 #include "G4LindhardPartition.hh"
0038
0039 #include "G4Element.hh"
0040 #include "G4Material.hh"
0041 #include "G4PhysicalConstants.hh"
0042 #include "G4SystemOfUnits.hh"
0043
0044 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0045 /*
0046 for a first cut, we will compute NIEL from a Lindhard-Robinson partition
0047 based on the most abundant element in the material.
0048
0049 this is from IEEE Trans. Nucl Science Vol. 48 No.1 February 2001 page 162++
0050 Insoo Jun, "Effects of Secondary Particles on the Total Dose..."
0051 and, by reference,
0052 Lindhard, Nielsen, Scharff & Thompson,
0053 "Integral Equations Governing Radiation Efects...",
0054 Mat. Fys. Medd. Dan. Vid. Selsk. vol 33 #10, pp1-42, 1963
0055 and
0056 Robinson, "The dependence of radiation effects on primary recoil energy",
0057 in Proc. Int. Conf. Radiation-Induced Voids in Metal,
0058 Albany, NY 1972 pp. 397-439
0059 def lindhard_robinson(z1, a1, z2, a2, ke):
0060 el=30.724*z1*z2*math.sqrt(z1**0.6667+z2**0.6667)*(a1+a2)/a2
0061 fl=0.0793*z1**0.6667*math.sqrt(z2)*(a1+a2)**1.5/
0062 ((z1**0.6667+z2**0.6667)**0.75*a1**1.5*math.sqrt(a2))
0063 eps=ke*(1.0/el)
0064 return 1.0/(1+fl*(3.4008*eps**0.16667+0.40244*eps**0.75+eps))
0065 */
0066
0067 G4LindhardRobinsonPartition::G4LindhardRobinsonPartition()
0068 {
0069   max_z = 120;
0070   for (size_t i = 1; i < max_z; i++) {
0071     z23[i] = std::pow((G4double)i, 2. / 3.);
0072   }
0073 }
0074
0075 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0076
0077 G4double G4LindhardRobinsonPartition::PartitionNIEL(G4int z1, G4double a1,
0078                                                     const G4Material* material,
0079                                                     G4double energy) const
0080 {
0081   size_t nMatElements = material->GetNumberOfElements();
0082
0083   const G4double* atomDensities = material->GetVecNbOfAtomsPerVolume();
0084   G4double maxdens = 0.0;
0085   size_t maxindex = 0;
0086   for (size_t k = 0; k < nMatElements; k++) {
0087     if (atomDensities[k] > maxdens) {
0088       maxdens = atomDensities[k];
0089       maxindex = k;
0090     }
0091   }
0092   const G4Element* element = material->GetElement(maxindex);
0093
0094   G4int z2 = G4int(element->GetZ());
0095
0096   G4double a2 = element->GetA() / (Avogadro * amu);
0097
0098   G4double zpow = z23[z1] + z23[z2];
0099   G4double asum = a1 + a2;
0100
0101   G4double el = 30.724 * z1 * z2 * std::sqrt(zpow) * asum / a2;
0102   G4double fl = 0.0793 * z23[z1] * std::sqrt(z2 * asum * asum * asum / (a1 * a1 * a1 * a2))
0103                 / std::pow(zpow, 0.75);
0104   G4double eps = (energy / eV) * (1.0 / el);
0105
0106   return 1.0 / (1 + fl * (3.4008 * std::pow(eps, 0.16667) + 0.40244 * std::pow(eps, 0.75) + eps));
0107 }