Gabriele Cosmo
214 lines
8.1 KiB
C++
214 lines
8.1 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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// $Id: G4ionEffectiveCharge.cc,v 1.6 2004/12/01 18:01:01 vnivanch Exp $
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// GEANT4 tag $Name: geant4-07-00-cand-03 $
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//
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// -------------------------------------------------------------------
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//
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// GEANT4 Class file
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//
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//
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// File name: G4ionEffectiveCharge
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//
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// Author: Vladimir Ivanchenko
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//
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// Creation date: 07.05.2002
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//
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// Modifications:
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// 12.09.2004 Set low energy limit to 1 keV (V.Ivanchenko)
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//
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// -------------------------------------------------------------------
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//
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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#include "G4ionEffectiveCharge.hh"
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#include "G4UnitsTable.hh"
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#include "G4ParticleDefinition.hh"
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#include "G4Material.hh"
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4ionEffectiveCharge::G4ionEffectiveCharge()
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{
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chargeCorrection = 1.0;
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// energyHighLimit = 1.*MeV;
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energyHighLimit = 25.*MeV;
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// energyLowLimit = 3.25*keV;
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energyLowLimit = 1.0*keV;
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energyBohr = 25.*keV;
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massFactor = amu_c2/(proton_mass_c2*keV);
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4ionEffectiveCharge::~G4ionEffectiveCharge()
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{}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4ionEffectiveCharge::EffectiveCharge(const G4ParticleDefinition* p,
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const G4Material* material,
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G4double kineticEnergy)
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{
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G4double mass = p->GetPDGMass();
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G4double charge = p->GetPDGCharge();
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G4double Zi = charge/eplus;
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chargeCorrection = 1.0;
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// The aproximation of ion effective charge from:
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// J.F.Ziegler, J.P. Biersack, U. Littmark
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// The Stopping and Range of Ions in Matter,
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// Vol.1, Pergamon Press, 1985
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// Fast ions or hadrons
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G4double reducedEnergy = kineticEnergy * proton_mass_c2/mass ;
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if( reducedEnergy > energyHighLimit || Zi < 1.5 ) return charge;
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static G4double vFermi[92] = {
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1.0309, 0.15976, 0.59782, 1.0781, 1.0486, 1.0, 1.058, 0.93942, 0.74562, 0.3424,
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0.45259, 0.71074, 0.90519, 0.97411, 0.97184, 0.89852, 0.70827, 0.39816, 0.36552, 0.62712,
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0.81707, 0.9943, 1.1423, 1.2381, 1.1222, 0.92705, 1.0047, 1.2, 1.0661, 0.97411,
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0.84912, 0.95, 1.0903, 1.0429, 0.49715, 0.37755, 0.35211, 0.57801, 0.77773, 1.0207,
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1.029, 1.2542, 1.122, 1.1241, 1.0882, 1.2709, 1.2542, 0.90094, 0.74093, 0.86054,
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0.93155, 1.0047, 0.55379, 0.43289, 0.32636, 0.5131, 0.695, 0.72591, 0.71202, 0.67413,
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0.71418, 0.71453, 0.5911, 0.70263, 0.68049, 0.68203, 0.68121, 0.68532, 0.68715, 0.61884,
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0.71801, 0.83048, 1.1222, 1.2381, 1.045, 1.0733, 1.0953, 1.2381, 1.2879, 0.78654,
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0.66401, 0.84912, 0.88433, 0.80746, 0.43357, 0.41923, 0.43638, 0.51464, 0.73087, 0.81065,
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1.9578, 1.0257} ;
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static G4double lFactor[92] = {
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1.0, 1.0, 1.1, 1.06, 1.01, 1.03, 1.04, 0.99, 0.95, 0.9,
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0.82, 0.81, 0.83, 0.88, 1.0, 0.95, 0.97, 0.99, 0.98, 0.97,
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0.98, 0.97, 0.96, 0.93, 0.91, 0.9, 0.88, 0.9, 0.9, 0.9,
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0.9, 0.85, 0.9, 0.9, 0.91, 0.92, 0.9, 0.9, 0.9, 0.9,
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0.9, 0.88, 0.9, 0.88, 0.88, 0.9, 0.9, 0.88, 0.9, 0.9,
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0.9, 0.9, 0.96, 1.2, 0.9, 0.88, 0.88, 0.85, 0.9, 0.9,
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0.92, 0.95, 0.99, 1.03, 1.05, 1.07, 1.08, 1.1, 1.08, 1.08,
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1.08, 1.08, 1.09, 1.09, 1.1, 1.11, 1.12, 1.13, 1.14, 1.15,
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1.17, 1.2, 1.18, 1.17, 1.17, 1.16, 1.16, 1.16, 1.16, 1.16,
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1.16, 1.16} ;
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static G4double c[6] = {0.2865, 0.1266, -0.001429,
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0.02402,-0.01135, 0.001475} ;
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// get elements in the actual material,
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const G4ElementVector* theElementVector = material->GetElementVector() ;
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const G4double* theAtomicNumDensityVector =
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material->GetAtomicNumDensityVector() ;
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const G4int NumberOfElements = material->GetNumberOfElements() ;
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// loop for the elements in the material
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// to find out average values Z, vF, lF
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G4double z = 0.0, vF = 0.0, lF = 0.0, norm = 0.0 ;
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if( 1 == NumberOfElements ) {
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z = material->GetZ() ;
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G4int iz = G4int(z) - 1 ;
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if(iz < 0) iz = 0 ;
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else if(iz > 91) iz = 91 ;
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vF = vFermi[iz] ;
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lF = lFactor[iz] ;
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} else {
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for (G4int iel=0; iel<NumberOfElements; iel++)
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{
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const G4Element* element = (*theElementVector)[iel] ;
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G4double z2 = element->GetZ() ;
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const G4double weight = theAtomicNumDensityVector[iel] ;
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norm += weight ;
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z += z2 * weight ;
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G4int iz = G4int(z2) - 1 ;
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if(iz < 0) iz = 0 ;
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else if(iz > 91) iz =91 ;
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vF += vFermi[iz] * weight ;
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lF += lFactor[iz] * weight ;
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}
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z /= norm ;
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vF /= norm ;
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lF /= norm ;
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}
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reducedEnergy = std::max(reducedEnergy,energyLowLimit);
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G4double q;
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// Helium ion case
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if( Zi < 2.5 ) {
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G4double Q = std::max(0.0,std::log(reducedEnergy*massFactor));
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G4double x = c[0];
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G4double y = 1.0;
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for (G4int i=1; i<6; i++) {
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y *= Q;
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x += y * c[i] ;
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}
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G4double tq = 7.6 - Q;
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q = (1.0 + ( 0.007 + 0.00005 * z ) * std::exp( -tq*tq )) * std::sqrt(1.0 - std::exp(-x)) ;
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// Heavy ion case
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} else {
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G4double z23 = std::pow(z, 0.666667);
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G4double zi13 = std::pow(Zi, 0.33333);
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G4double zi23 = zi13*zi13;
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reducedEnergy = std::max(reducedEnergy,energyBohr/z23);
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// v1 is ion velocity in vF unit
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G4double v1 = std::sqrt( reducedEnergy / energyBohr )/ vF ;
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G4double y ;
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// Faster than Fermi velocity
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if ( v1 > 1.0 ) {
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y = vF * v1 * ( 1.0 + 0.2 / (v1*v1) ) / zi23 ;
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// Slower than Fermi velocity
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} else {
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y = 0.6923 * vF * (1.0 + 2.0*v1*v1/3.0 + v1*v1*v1*v1/15.0) / zi23 ;
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}
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G4double y3 = std::pow(y, 0.3) ;
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// G4cout << "y= " << y << " y3= " << y3 << " v1= " << v1 << " vF= " << vF << G4endl;
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q = 1.0 - std::exp( 0.803*y3 - 1.3167*y3*y3 - 0.38157*y - 0.008983*y*y ) ;
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if(q < 0.0) q = 0.0;
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G4double tq = 7.6 - std::log(reducedEnergy/keV);
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G4double sq = 1.0 + ( 0.18 + 0.0015 * z ) * std::exp( -tq*tq )/ (Zi*Zi);
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// Screen length according to
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// J.F.Ziegler and J.M.Manoyan, The stopping of ions in compaunds,
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// Nucl. Inst. & Meth. in Phys. Res. B35 (1988) 215-228.
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G4double lambda = 10.0 * vF * std::pow(1.0-q, 0.6667) / (zi13 * (6.0 + q)) ;
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chargeCorrection = sq * (q + 0.5*(1.0 - q)*std::log(1.0 + lambda*lambda)/(vF*vF) );
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if(q > 0.0) chargeCorrection /= q;
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}
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// G4cout << "G4ionEffectiveCharge: charge= " << charge << " q= " << q
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// << " chargeCor= " << chargeCorrection
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// << " e(MeV)= " << kineticEnergy/MeV << G4endl;
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return q*charge;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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