field04/src/F04FocusSolenoid.cc

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0026 //
0027 /// \file field/field04/src/F04FocusSolenoid.cc
0028 /// \brief Implementation of the F04FocusSolenoid class
0029 //
0030
0031 #include "F04FocusSolenoid.hh"
0032
0033 #include "F04GlobalField.hh"
0034 #include "F04SimpleSolenoid.hh"
0035
0036 #include "G4GeometryManager.hh"
0037 #include "globals.hh"
0038
0039 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0040
0041 F04FocusSolenoid::F04FocusSolenoid(G4double Ba, G4double Bb, G4double fz, G4LogicalVolume* lv,
0042                                    G4ThreeVector c)
0043   : F04SimpleSolenoid(Ba, fz, lv, c), fB1(Ba), fB2(Bb)
0044 {}
0045
0046 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0047
0048 void F04FocusSolenoid::AddFieldValue(const G4double point[4], G4double field[6]) const
0049 {
0050   G4ThreeVector global(point[0], point[1], point[2]);
0051
0052   G4ThreeVector local = fGlobal2local.TransformPoint(global);
0053
0054   if (IsOutside(local)) return;
0055
0056   G4double length = ((F04SimpleSolenoid*)this)->GetLength();
0057
0058   G4double Bz = (fB2 - fB1) * std::abs(local.z()) / (length / 2.) + fB1;
0059
0060   if (fHalf) {
0061     if (local.z() >= 0.) Bz = fB1;
0062   }
0063
0064   G4ThreeVector B(0.0, 0.0, Bz);
0065
0066   B = fGlobal2local.Inverse().TransformAxis(B);
0067
0068   field[0] += B[0];
0069   field[1] += B[1];
0070   field[2] += B[2];
0071 }