| 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 | // $Id: G4NeutronHPMadlandNixSpectrum.hh,v 1.12 2006/06/29 20:48:33 gunter Exp $
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| 28 | // GEANT4 tag $Name: geant4-09-03-cand-01 $
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| 29 | //
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| 30 | #ifndef G4NeutronHPMadlandNixSpectrum_h
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| 31 | #define G4NeutronHPMadlandNixSpectrum_h 1
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| 32 |
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| 33 | #include "globals.hh"
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| 34 | #include "G4NeutronHPVector.hh"
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| 35 | #include "Randomize.hh"
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| 36 | #include "G4ios.hh"
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| 37 | #include <fstream>
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| 38 | #include <cmath>
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| 39 | #include "G4VNeutronHPEDis.hh"
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| 40 |
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| 41 | // #include <nag.h> @
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| 42 | // #include <nags.h> @
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| 43 |
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| 44 |
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| 45 | // we will need a List of these .... one per term.
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| 46 |
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| 47 | class G4NeutronHPMadlandNixSpectrum : public G4VNeutronHPEDis
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| 48 | {
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| 49 | public:
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| 50 | G4NeutronHPMadlandNixSpectrum()
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| 51 | {
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| 52 | expm1 = std::exp(-1.);
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| 53 | }
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| 54 | ~G4NeutronHPMadlandNixSpectrum()
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| 55 | {
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| 56 | }
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| 57 |
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| 58 | inline void Init(std::ifstream & aDataFile)
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| 59 | {
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| 60 | theFractionalProb.Init(aDataFile);
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| 61 | aDataFile>> theAvarageKineticPerNucleonForLightFragments;
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| 62 | theAvarageKineticPerNucleonForLightFragments*=eV;
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| 63 | aDataFile>> theAvarageKineticPerNucleonForHeavyFragments;
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| 64 | theAvarageKineticPerNucleonForHeavyFragments*=eV;
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| 65 | theMaxTemp.Init(aDataFile);
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| 66 | }
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| 67 |
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| 68 | inline G4double GetFractionalProbability(G4double anEnergy)
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| 69 | {
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| 70 | return theFractionalProb.GetY(anEnergy);
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| 71 | }
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| 72 |
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| 73 | G4double Sample(G4double anEnergy);
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| 74 |
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| 75 | private:
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| 76 |
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| 77 | G4double Madland(G4double aSecEnergy, G4double tm);
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| 78 |
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| 79 | inline G4double FissionIntegral(G4double tm, G4double anEnergy)
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| 80 | {
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| 81 | return 0.5*( GIntegral(tm, anEnergy, theAvarageKineticPerNucleonForLightFragments)
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| 82 | +GIntegral(tm, anEnergy, theAvarageKineticPerNucleonForHeavyFragments) );
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| 83 | }
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| 84 |
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| 85 | G4double GIntegral(G4double tm, G4double anEnergy, G4double aMean);
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| 86 |
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| 87 | inline G4double Gamma05(G4double aValue)
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| 88 | {
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| 89 | G4double result;
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| 90 | // gamma(1.2,x*X) = std::sqrt(pi)*Erf(x)
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| 91 | G4double x = std::sqrt(aValue);
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| 92 | G4double t = 1./(1+0.47047*x);
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| 93 | result = 1- (0.3480242*t - 0.0958798*t*t + 0.7478556*t*t*t)*std::exp(-aValue); // @ check
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| 94 | result *= std::sqrt(pi);
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| 95 | return result;
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| 96 | }
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| 97 |
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| 98 | inline G4double Gamma15(G4double aValue)
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| 99 | {
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| 100 | G4double result;
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| 101 | // gamma(a+1, x) = a*gamma(a,x)-x**a*std::exp(-x)
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| 102 | result = 0.5*Gamma05(aValue) - std::sqrt(aValue)*std::exp(-aValue); // @ check
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| 103 | return result;
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| 104 | }
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| 105 |
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| 106 | inline G4double Gamma25(G4double aValue)
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| 107 | {
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| 108 | G4double result;
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| 109 | result = 1.5*Gamma15(aValue) - std::pow(aValue,1.5)*std::exp(aValue); // @ check
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| 110 | return result;
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| 111 | }
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| 112 |
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| 113 | inline G4double E1(G4double aValue)
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| 114 | {
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| 115 | // good only for rather low aValue @@@ replace by the corresponding NAG function for the
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| 116 | // exponential integral. (<5 seems ok.
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| 117 | G4double gamma = 0.577216;
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| 118 | G4double precision = 0.000001;
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| 119 | G4double result =-gamma - std::log(aValue);
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| 120 | G4double term = -aValue;
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| 121 | G4double last;
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| 122 | G4int count = 1;
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| 123 | result -= term;
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| 124 | for(;;)
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| 125 | {
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| 126 | count++;
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| 127 | last = result;
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| 128 | term = -term*aValue*(count-1)/(count*count);
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| 129 | result -=term;
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| 130 | if(std::fabs(term)/std::fabs(result)<precision) break;
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| 131 | }
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| 132 | // NagError *fail; @
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| 133 | // result = nag_exp_integral(aValue, fail); @
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| 134 | return result;
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| 135 | }
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| 136 |
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| 137 | private:
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| 138 |
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| 139 | G4double expm1;
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| 140 |
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| 141 | private:
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| 142 |
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| 143 | G4NeutronHPVector theFractionalProb;
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| 144 |
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| 145 | G4double theAvarageKineticPerNucleonForLightFragments;
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| 146 | G4double theAvarageKineticPerNucleonForHeavyFragments;
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| 147 |
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| 148 | G4NeutronHPVector theMaxTemp;
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| 149 |
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| 150 | };
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| 151 |
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| 152 | #endif
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