| Geant4 Cross Reference |
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34 // ********************************************************************
35 //
36 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
37 //
38 // MODULE: G4EMDissociationSpectrum.cc
39 //
40 // Version: B.1
41 // Date: 15/04/04
42 // Author: P R Truscott
43 // Organisation: QinetiQ Ltd, UK
44 // Customer: ESA/ESTEC, NOORDWIJK
45 // Contract: 17191/03/NL/LvH
46 //
47 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
48 //
49 // CHANGE HISTORY
50 // --------------
51 //
52 // 6 October 2003, P R Truscott, QinetiQ Ltd, UK
53 // Created.
54 //
55 // 15 March 2004, P R Truscott, QinetiQ Ltd, UK
56 // Beta release
57 //
58 // %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
59 ////////////////////////////////////////////////////////////////////////////////
60 //
61 #include "G4EMDissociationSpectrum.hh"
62 #include "globals.hh"
63 #include "G4PhysicalConstants.hh"
64 #include "G4SystemOfUnits.hh"
65 #include "G4Pow.hh"
66
67 ////////////////////////////////////////////////////////////////////////////////
68 //
69 G4EMDissociationSpectrum::G4EMDissociationSpectrum ()
70 {
71 bessel = new G4Bessel();
72 }
73 ////////////////////////////////////////////////////////////////////////////////
74 //
75 G4EMDissociationSpectrum::~G4EMDissociationSpectrum ()
76 {
77 delete bessel;
78 }
79 ////////////////////////////////////////////////////////////////////////////////
80 //
81 G4double G4EMDissociationSpectrum::GetGeneralE1Spectrum
82 (G4double Eg, G4double b, G4double bmin)
83 {
84 G4double b2 = b*b;
85 G4double gg = 1.0/std::sqrt(1.0-b2);
86 G4double xi = Eg * bmin / gg / b / hbarc;
87 G4double K0 = bessel->K0(xi);
88 G4double K1 = bessel->K1(xi);
89 G4double n = 2.0 * fine_structure_const / pi / b2 / Eg *
90 (xi*K0*K1 - xi*xi*b2/2.0*(K1*K1-K0*K0));
91 return n;
92 }
93 ////////////////////////////////////////////////////////////////////////////////
94 //
95 G4double G4EMDissociationSpectrum::GetGeneralE2Spectrum
96 (G4double Eg, G4double b, G4double bmin)
97 {
98 G4double b2 = b * b;
99 G4double b4 = b2 * b2;
100 G4double gg = 1.0/std::sqrt(1.0-b2);
101 G4double xi = Eg * bmin / gg / b / hbarc;
102 G4double K0 = bessel->K0(xi);
103 G4double K1 = bessel->K1(xi);
104 G4double n = 2.0 * fine_structure_const / pi / b4 / Eg *
105 (2.0*(1.0-b2)*K1*K1 + xi*G4Pow::GetInstance()->powA((2.0-b2),2.0)*K0*K1 -
106 xi*xi*b4/2.0*(K1*K1-K0*K0));
107 return n;
108 }
109 ////////////////////////////////////////////////////////////////////////////////
110 //
111 G4double G4EMDissociationSpectrum::GetClosestApproach
112 (const G4double AP, const G4double ZP, G4double AT, G4double ZT, G4double b)
113 {
114 G4double bsq = b * b;
115 G4double gg = 1.0/std::sqrt(1-bsq);
116 G4double AProot3 = G4Pow::GetInstance()->powA(AP,1.0/3.0);
117 G4double ATroot3 = G4Pow::GetInstance()->powA(AT,1.0/3.0);
118 G4double bc = 1.34 * fermi * (AProot3+ATroot3 - 0.75 *(1.0/AProot3+1.0/ATroot3));
119 // G4double a0 = ZP * ZT * classic_electr_radius/bsq;
120 G4double a0 = ZP * ZT * elm_coupling / (AT*AP*amu_c2/(AT+AP)) / bsq;
121 G4double bmin = 1.25 * bc + halfpi*a0/gg;
122 return bmin;
123 }
124 ////////////////////////////////////////////////////////////////////////////////
125 //
126