[819] | 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 7 | // * conditions of the Geant4 Software License, included in the file * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // |
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| 27 | // ------------------------------------------------------------------- |
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| 28 | // GEANT 4 class implementation file |
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| 29 | // |
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| 30 | // CERN, Geneva, Switzerland |
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| 31 | // |
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| 32 | // File name: G4KM_NucleonEqRhs.cc |
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| 33 | // |
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| 34 | // Author: Alessandro Brunengo (Alessandro.Brunengo@ge.infn.it) |
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| 35 | // |
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| 36 | // Creation date: 5 June 2000 |
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| 37 | // ------------------------------------------------------------------- |
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| 38 | |
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| 39 | #include "G4KM_NucleonEqRhs.hh" |
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| 40 | #include "G4VNuclearDensity.hh" |
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| 41 | |
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| 42 | |
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| 43 | G4KM_NucleonEqRhs::G4KM_NucleonEqRhs(G4KM_DummyField *field, |
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| 44 | G4V3DNucleus * nucleus) : |
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| 45 | G4Mag_EqRhs(field), theNucleus(nucleus) |
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| 46 | { |
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| 47 | theMass = 0.; |
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| 48 | A = theNucleus->GetMassNumber(); |
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| 49 | factor = hbarc*hbarc*std::pow(3.*pi2*A,2./3.)/3.; |
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| 50 | } |
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| 51 | |
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| 52 | |
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| 53 | void G4KM_NucleonEqRhs::EvaluateRhsGivenB(const G4double y[], |
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| 54 | const G4double *, |
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| 55 | G4double dydx[]) const |
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| 56 | { |
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| 57 | G4double yMod = std::sqrt(y[0]*y[0]+y[1]*y[1]+y[2]*y[2]); |
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| 58 | G4double e = std::sqrt(theMass*theMass+y[3]*y[3]+y[4]*y[4]+y[5]*y[5]); |
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| 59 | |
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| 60 | // y[0..2] is position |
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| 61 | // y[3..5] is momentum (and not mom.direction) |
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| 62 | |
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| 63 | dydx[0] = c_light*y[3]/e; // |
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| 64 | dydx[1] = c_light*y[4]/e; // dq/dt=dH/dp = c*p/e |
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| 65 | dydx[2] = c_light*y[5]/e; // |
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| 66 | |
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| 67 | /* |
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| 68 | * // debug |
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| 69 | * G4cout << " Nucleon RHS : 0..2(dpos/dt) " << |
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| 70 | * dydx[0] << " " << |
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| 71 | * dydx[1] << " " << |
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| 72 | * dydx[2] << " " << G4endl; |
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| 73 | */ |
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| 74 | |
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| 75 | |
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| 76 | // V=K*rho(r) ==> dydx[3] = -dV/dr*dr/dx = -K*d(rho)/dr*dr/dx. |
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| 77 | // GF should be V=K*rho(r) ==> dydx[3] = -dV/dr*dr/dx = -K*d(rho)/dr*dr/dt |
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| 78 | // GF and dV/dt = dE/dt ==> dp/dt = dE/dt * dp/dE = dE/dt *e/p |
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| 79 | // Idem for dydx[4] and dydx[5] |
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| 80 | |
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| 81 | G4ThreeVector pos(y[0],y[1],y[2]); |
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| 82 | |
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| 83 | const G4VNuclearDensity * nuclearDensity=theNucleus->GetNuclearDensity(); |
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| 84 | |
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| 85 | // do not check for theMass != 0 : it is an error and core dump will signal it |
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| 86 | |
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| 87 | G4double density= nuclearDensity->GetDensity(pos); |
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| 88 | G4double deriv(0); |
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| 89 | if (density > 0 ) deriv = (factor/theMass)* |
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| 90 | std::pow(density, -1./3.)*nuclearDensity->GetDeriv(pos); |
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| 91 | |
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| 92 | // dydx[3] = yMod == 0 ? 0 : -deriv*y[0]/yMod; |
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| 93 | // dydx[4] = yMod == 0 ? 0 : -deriv*y[1]/yMod; |
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| 94 | // dydx[5] = yMod == 0 ? 0 : -deriv*y[2]/yMod; |
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| 95 | dydx[3] = yMod == 0 ? 0 : deriv*y[0]/yMod*c_light; |
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| 96 | dydx[4] = yMod == 0 ? 0 : deriv*y[1]/yMod*c_light; |
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| 97 | dydx[5] = yMod == 0 ? 0 : deriv*y[2]/yMod*c_light; |
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| 98 | |
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| 99 | |
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| 100 | /* |
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| 101 | * // debug |
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| 102 | * G4cout << " Nucleon RHS : 3..5(dE/dt) " << |
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| 103 | * dydx[3] << " " << |
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| 104 | * dydx[4] << " " << |
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| 105 | * dydx[5] << " " << G4endl; |
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| 106 | */ |
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| 107 | } |
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| 108 | |
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| 109 | |
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| 110 | |
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| 111 | |
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