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26 /*
27 * \file electromagnetic/TestEm7/src/G4LindhardPartition.cc
28 * \brief Implementation of the G4LindhardPartition class
29 *
30 * Created by Marcus Mendenhall on 1/14/08.
31 * 2008 Vanderbilt University, Nashville, TN, USA.
32 *
33 */
34
35 //
36
37 #include "G4LindhardPartition.hh"
38
39 #include "G4Element.hh"
40 #include "G4Material.hh"
41 #include "G4PhysicalConstants.hh"
42 #include "G4SystemOfUnits.hh"
43
44 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
45 /*
46 for a first cut, we will compute NIEL from a Lindhard-Robinson partition
47 based on the most abundant element in the material.
48
49 this is from IEEE Trans. Nucl Science Vol. 48 No.1 February 2001 page 162++
50 Insoo Jun, "Effects of Secondary Particles on the Total Dose..."
51 and, by reference,
52 Lindhard, Nielsen, Scharff & Thompson,
53 "Integral Equations Governing Radiation Efects...",
54 Mat. Fys. Medd. Dan. Vid. Selsk. vol 33 #10, pp1-42, 1963
55 and
56 Robinson, "The dependence of radiation effects on primary recoil energy",
57 in Proc. Int. Conf. Radiation-Induced Voids in Metal,
58 Albany, NY 1972 pp. 397-439
59 def lindhard_robinson(z1, a1, z2, a2, ke):
60 el=30.724*z1*z2*math.sqrt(z1**0.6667+z2**0.6667)*(a1+a2)/a2
61 fl=0.0793*z1**0.6667*math.sqrt(z2)*(a1+a2)**1.5/
62 ((z1**0.6667+z2**0.6667)**0.75*a1**1.5*math.sqrt(a2))
63 eps=ke*(1.0/el)
64 return 1.0/(1+fl*(3.4008*eps**0.16667+0.40244*eps**0.75+eps))
65 */
66
67 G4LindhardRobinsonPartition::G4LindhardRobinsonPartition()
68 {
69 max_z = 120;
70 for (size_t i = 1; i < max_z; i++) {
71 z23[i] = std::pow((G4double)i, 2. / 3.);
72 }
73 }
74
75 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
76
77 G4double G4LindhardRobinsonPartition::PartitionNIEL(G4int z1, G4double a1,
78 const G4Material* material,
79 G4double energy) const
80 {
81 size_t nMatElements = material->GetNumberOfElements();
82
83 const G4double* atomDensities = material->GetVecNbOfAtomsPerVolume();
84 G4double maxdens = 0.0;
85 size_t maxindex = 0;
86 for (size_t k = 0; k < nMatElements; k++) {
87 if (atomDensities[k] > maxdens) {
88 maxdens = atomDensities[k];
89 maxindex = k;
90 }
91 }
92 const G4Element* element = material->GetElement(maxindex);
93
94 G4int z2 = G4int(element->GetZ());
95
96 G4double a2 = element->GetA() / (Avogadro * amu);
97
98 G4double zpow = z23[z1] + z23[z2];
99 G4double asum = a1 + a2;
100
101 G4double el = 30.724 * z1 * z2 * std::sqrt(zpow) * asum / a2;
102 G4double fl = 0.0793 * z23[z1] * std::sqrt(z2 * asum * asum * asum / (a1 * a1 * a1 * a2))
103 / std::pow(zpow, 0.75);
104 G4double eps = (energy / eV) * (1.0 / el);
105
106 return 1.0 / (1 + fl * (3.4008 * std::pow(eps, 0.16667) + 0.40244 * std::pow(eps, 0.75) + eps));
107 }
108