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G4PolarizedComptonCrossSection.hh
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26 // $Id: G4PolarizedComptonCrossSection.hh 96114 2016-03-16 18:51:33Z gcosmo $
27 //
28 // GEANT4 Class file
29 //
30 //
31 // File name: G4PolarizedComptonCrossSection
32 //
33 // Author: Andreas Schaelicke
34 //
35 // Creation date: 15.05.2005
36 //
37 // Modifications:
38 // 18-07-06 use newly calculated cross sections (P. Starovoitov)
39 // 21-08-06 update interface to geant4.8.1 (A. Schaelicke)
40 // 15-10-07 introduced a more general framework for cross sections (AS)
41 //
42 //
43 // Class Description:
44 // determine the polarization of the final state
45 // in a Compton scattering process employing the differential
46 // cross section by F.W.Lipps & H.A.Tolhoek
47 // ( Physica 20 (1954) 395 )
48 //
49 #ifndef G4PolarizedComptonCrossSection_h
50 #define G4PolarizedComptonCrossSection_h 1
51 
52 #include "G4StokesVector.hh"
54 
55 
56 
58 {
59 public:
62 public:
63  // prepares the ingredients for the calculation of a polarization
64  // dependent differential cross section
65  // the kinematics is fixed (X - incoming photon energy in units of electron mass,
66  // eps - outgoing photon energy in unit of incoming photon energy,
67  // and polarization of the incoming particles fixed (p0, p1)
68  // a flag specifies the extent to which polarization is taken
69  // into account
70  virtual void Initialize(G4double eps, G4double X, G4double phi,
71  const G4StokesVector & p0,
72  const G4StokesVector & p1,
73  G4int flag=0) override;
74 
75  // returns the differential cross section for a given polarisation state
76  // of the final state particles to be used in the calculation of the
77  // polarization transfer
78  // the calculation has to be initialised by calling Initialize()
79  // prior to the first call of this function (see above)
80  G4double XSection(const G4StokesVector & pol2,const G4StokesVector & pol3) override;
81  // total cross section
83  const G4StokesVector & pol0,const G4StokesVector & pol1) override;
84 
85 public:
86  // return expected mean polarisation
87  G4StokesVector GetPol2() override;
88  G4StokesVector GetPol3() override;
89 private:
90  void DefineCoefficients(const G4StokesVector & pol0,
91  const G4StokesVector & pol1);
92  // states if an incoming or outgoing particle is polarized
93  G4bool gammaPol2, electronPol3;
94 
95  // these variables store the information necessary to evaluate the
96  // differential cross section for arbitrary final state
97  // polarizations (used in XSection):
98  // - polarization independent part
99  G4double phi0;
100  // - part depending on the polarization of the final photon
101  G4ThreeVector phi2;
102  // - part depending on the polarization of the final electron
103  G4ThreeVector phi3;
104  // - product of polarizations of initial particles
105  G4double polxx, polyy, polzz, polxz, polzx, polyz, polzy, polxy, polyx;
106 
107  G4double diffXSFactor, totalXSFactor, re2;
108  G4double polXS, unpXS;
109 };
110 
111 
112 #endif
static const G4double eps
int G4int
Definition: G4Types.hh:78
G4double TotalXSection(G4double xmin, G4double xmax, G4double y, const G4StokesVector &pol0, const G4StokesVector &pol1) override
bool G4bool
Definition: G4Types.hh:79
virtual void Initialize(G4double eps, G4double X, G4double phi, const G4StokesVector &p0, const G4StokesVector &p1, G4int flag=0) override
G4double XSection(const G4StokesVector &pol2, const G4StokesVector &pol3) override
double G4double
Definition: G4Types.hh:76