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96686e0c8f4994abca7e1ccf08ac315c6d680b1e
geant4/source/processes/hadronic/models/coherent_elastic/src/G4LEnp.cc
T
Gabriele Cosmo 96686e0c8f Import Geant4 6.0.0 source tree
2016-06-09 10:41:53 +02:00

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//
// ********************************************************************
// * DISCLAIMER *
// * *
// * The following disclaimer summarizes all the specific disclaimers *
// * of contributors to this software. The specific disclaimers,which *
// * govern, are listed with their locations in: *
// * http://cern.ch/geant4/license *
// * *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work make any representation or warranty, express or implied, *
// * regarding this software system or assume any liability for its *
// * use. *
// * *
// * This code implementation is the intellectual property of the *
// * GEANT4 collaboration. *
// * By copying, distributing or modifying the Program (or any work *
// * based on the Program) you indicate your acceptance of this *
// * statement, and all its terms. *
// ********************************************************************
//
// G4 Low energy model: n-p scattering
// F.W. Jones, L.G. Greeniaus, H.P. Wellisch
#include "G4LEnp.hh"
#include "Randomize.hh"
#include "G4ios.hh"
// Initialization of static data arrays:
#include "G4LEnpData.hh"
#include "Randomize.hh"
G4LEnp::G4LEnp() :
G4HadronicInteraction()
{
// theParticleChange.SetNumberOfSecondaries(1);
// SetMinEnergy(10.*MeV);
// SetMaxEnergy(1200.*MeV);
SetMinEnergy(0.);
SetMaxEnergy(1200.*GeV);
}
G4LEnp::~G4LEnp()
{
theParticleChange.Clear();
}
G4HadFinalState*
G4LEnp::ApplyYourself(const G4HadProjectile& aTrack, G4Nucleus& targetNucleus)
{
theParticleChange.Clear();
const G4HadProjectile* aParticle = &aTrack;
G4double P = aParticle->GetTotalMomentum();
G4double Px = aParticle->Get4Momentum().x();
G4double Py = aParticle->Get4Momentum().y();
G4double Pz = aParticle->Get4Momentum().z();
G4double ek = aParticle->GetKineticEnergy();
G4ThreeVector theInitial = aParticle->Get4Momentum().vect();
if (verboseLevel > 1) {
G4double E = aParticle->GetTotalEnergy();
G4double E0 = aParticle->GetDefinition()->GetPDGMass();
G4double Q = aParticle->GetDefinition()->GetPDGCharge();
G4double N = targetNucleus.GetN();
G4double Z = targetNucleus.GetZ();
G4cout << "G4LEnp:ApplyYourself: incident particle: "
<< aParticle->GetDefinition()->GetParticleName() << G4endl;
G4cout << "P = " << P/GeV << " GeV/c"
<< ", Px = " << Px/GeV << " GeV/c"
<< ", Py = " << Py/GeV << " GeV/c"
<< ", Pz = " << Pz/GeV << " GeV/c" << G4endl;
G4cout << "E = " << E/GeV << " GeV"
<< ", kinetic energy = " << ek/GeV << " GeV"
<< ", mass = " << E0/GeV << " GeV"
<< ", charge = " << Q << G4endl;
G4cout << "G4LEnp:ApplyYourself: material:" << G4endl;
G4cout << "A = " << N
<< ", Z = " << Z
<< ", atomic mass "
<< G4Proton::Proton()->GetPDGMass()/GeV << "GeV"
<< G4endl;
//
// GHEISHA ADD operation to get total energy, mass, charge
//
E += G4Proton::Proton()->GetPDGMass();
G4double E02 = E*E - P*P;
E0 = sqrt(abs(E02));
if (E02 < 0)E0 *= -1;
Q += Z;
G4cout << "G4LEnp:ApplyYourself: total:" << G4endl;
G4cout << "E = " << E/GeV << " GeV"
<< ", mass = " << E0/GeV << " GeV"
<< ", charge = " << Q << G4endl;
}
// Find energy bin
G4int je1 = 0;
G4int je2 = NENERGY - 1;
ek = ek/GeV;
do {
G4int midBin = (je1 + je2)/2;
if (ek < elab[midBin])
je2 = midBin;
else
je1 = midBin;
} while (je2 - je1 > 1);
// G4int j;
//abs(ek-elab[je1]) < abs(ek-elab[je2]) ? j = je1 : j = je2;
G4double delab = elab[je2] - elab[je1];
// Sample the angle
G4float sample = G4UniformRand();
G4int ke1 = 0;
G4int ke2 = NANGLE - 1;
G4double dsig = sig[je2][0] - sig[je1][0];
G4double rc = dsig/delab;
G4double b = sig[je1][0] - rc*elab[je1];
G4double sigint1 = rc*ek + b;
G4double sigint2 = 0.;
if (verboseLevel > 1) G4cout << "sample=" << sample << G4endl
<< ke1 << " " << ke2 << " "
<< sigint1 << " " << sigint2 << G4endl;
do {
G4int midBin = (ke1 + ke2)/2;
dsig = sig[je2][midBin] - sig[je1][midBin];
rc = dsig/delab;
b = sig[je1][midBin] - rc*elab[je1];
G4double sigint = rc*ek + b;
if (sample < sigint) {
ke2 = midBin;
sigint2 = sigint;
}
else {
ke1 = midBin;
sigint1 = sigint;
}
if (verboseLevel > 1)G4cout << ke1 << " " << ke2 << " "
<< sigint1 << " " << sigint2 << G4endl;
} while (ke2 - ke1 > 1);
// sigint1 and sigint2 should be recoverable from above loop
// G4double dsig = sig[je2][ke1] - sig[je1][ke1];
// G4double rc = dsig/delab;
// G4double b = sig[je1][ke1] - rc*elab[je1];
// G4double sigint1 = rc*ek + b;
// G4double dsig = sig[je2][ke2] - sig[je1][ke2];
// G4double rc = dsig/delab;
// G4double b = sig[je1][ke2] - rc*elab[je1];
// G4double sigint2 = rc*ek + b;
dsig = sigint2 - sigint1;
rc = 1./dsig;
b = ke1 - rc*sigint1;
G4double kint = rc*sample + b;
G4double theta = (0.5 + kint)*pi/180.;
// G4int k;
//abs(sample-sig[j][ke1]) < abs(sample-sig[j][ke2]) ? k = ke1 : k = ke2;
// G4double theta = (0.5 + k)*pi/180.;
if (verboseLevel > 1) {
G4cout << " energy bin " << je1 << " energy=" << elab[je1] << G4endl;
G4cout << " angle bin " << kint << " angle=" << theta/degree << G4endl;
}
// Get the target particle
G4DynamicParticle* targetParticle = targetNucleus.ReturnTargetParticle();
G4double E1 = aParticle->GetTotalEnergy();
G4double M1 = aParticle->GetDefinition()->GetPDGMass();
G4double E2 = targetParticle->GetTotalEnergy();
G4double M2 = targetParticle->GetDefinition()->GetPDGMass();
G4double totalEnergy = E1 + E2;
G4double pseudoMass = sqrt(totalEnergy*totalEnergy - P*P);
// pseudoMass also = sqrt(M1*M1 + M2*M2 + 2*M2*E1)
// Transform into centre of mass system
G4double px = (M2/pseudoMass)*Px;
G4double py = (M2/pseudoMass)*Py;
G4double pz = (M2/pseudoMass)*Pz;
G4double p = sqrt(px*px + py*py + pz*pz);
if (verboseLevel > 1) {
G4cout << " E1, M1 (GeV) " << E1/GeV << " " << M1/GeV << G4endl;
G4cout << " E2, M2 (GeV) " << E2/GeV << " " << M2/GeV << G4endl;
G4cout << " particle 1 momentum in CM " << px/GeV << " " << py/GeV << " "
<< pz/GeV << " " << p/GeV << G4endl;
}
// First scatter w.r.t. Z axis
G4double phi = G4UniformRand()*twopi;
G4double pxnew = p*sin(theta)*cos(phi);
G4double pynew = p*sin(theta)*sin(phi);
G4double pznew = p*cos(theta);
// Rotate according to the direction of the incident particle
if (px*px + py*py > 0) {
G4double cost, sint, ph, cosp, sinp;
cost = pz/p;
sint = (sqrt(abs((1-cost)*(1+cost))) + sqrt(px*px+py*py)/p)/2;
py < 0 ? ph = 3*halfpi : ph = halfpi;
if (abs(px) > 0.000001*GeV) ph = atan2(py,px);
cosp = cos(ph);
sinp = sin(ph);
px = (cost*cosp*pxnew - sinp*pynew + sint*cosp*pznew);
py = (cost*sinp*pxnew + cosp*pynew + sint*sinp*pznew);
pz = (-sint*pxnew + cost*pznew);
// G4ThreeVector it(a,b,c);
// p0->SetMomentum(it);
// G4ThreeVector aTargetMom = theInitial - it;
// targetParticle->SetMomentum(aTargetMom);
}
else {
px = pxnew;
py = pynew;
pz = pznew;
}
if (verboseLevel > 1) {
G4cout << " AFTER SCATTER..." << G4endl;
G4cout << " particle 1 momentum in CM " << px/GeV << " " << py/GeV << " "
<< pz/GeV << " " << p/GeV << G4endl;
}
// Transform to lab system
G4double E1pM2 = E1 + M2;
G4double betaCM = P/E1pM2;
G4double betaCMx = Px/E1pM2;
G4double betaCMy = Py/E1pM2;
G4double betaCMz = Pz/E1pM2;
G4double gammaCM = E1pM2/sqrt(E1pM2*E1pM2 - P*P);
if (verboseLevel > 1) {
G4cout << " betaCM " << betaCMx << " " << betaCMy << " "
<< betaCMz << " " << betaCM << G4endl;
G4cout << " gammaCM " << gammaCM << G4endl;
}
// Now following GLOREN...
G4double BETA[5], PA[5], PB[5];
BETA[1] = -betaCMx;
BETA[2] = -betaCMy;
BETA[3] = -betaCMz;
BETA[4] = gammaCM;
//The incident particle...
PA[1] = px;
PA[2] = py;
PA[3] = pz;
PA[4] = sqrt(M1*M1 + p*p);
G4double BETPA = BETA[1]*PA[1] + BETA[2]*PA[2] + BETA[3]*PA[3];
G4double BPGAM = (BETPA * BETA[4]/(BETA[4] + 1.) - PA[4]) * BETA[4];
PB[1] = PA[1] + BPGAM * BETA[1];
PB[2] = PA[2] + BPGAM * BETA[2];
PB[3] = PA[3] + BPGAM * BETA[3];
PB[4] = (PA[4] - BETPA) * BETA[4];
G4DynamicParticle* newP = new G4DynamicParticle;
newP->SetDefinition(const_cast<G4ParticleDefinition *>(aParticle->GetDefinition()));
newP->SetMomentum(G4ThreeVector(PB[1], PB[2], PB[3]));
//The target particle...
PA[1] = -px;
PA[2] = -py;
PA[3] = -pz;
PA[4] = sqrt(M2*M2 + p*p);
BETPA = BETA[1]*PA[1] + BETA[2]*PA[2] + BETA[3]*PA[3];
BPGAM = (BETPA * BETA[4]/(BETA[4] + 1.) - PA[4]) * BETA[4];
PB[1] = PA[1] + BPGAM * BETA[1];
PB[2] = PA[2] + BPGAM * BETA[2];
PB[3] = PA[3] + BPGAM * BETA[3];
PB[4] = (PA[4] - BETPA) * BETA[4];
targetParticle->SetMomentum(G4ThreeVector(PB[1], PB[2], PB[3]));
if (verboseLevel > 1) {
G4cout << " particle 1 momentum in LAB "
<< newP->GetMomentum()*(1./GeV)
<< " " << newP->GetTotalMomentum()/GeV << G4endl;
G4cout << " particle 2 momentum in LAB "
<< targetParticle->GetMomentum()*(1./GeV)
<< " " << targetParticle->GetTotalMomentum()/GeV << G4endl;
G4cout << " TOTAL momentum in LAB "
<< (newP->GetMomentum()+targetParticle->GetMomentum())*(1./GeV)
<< " "
<< (newP->GetMomentum()+targetParticle->GetMomentum()).mag()/GeV
<< G4endl;
}
// charge symmetry....
if(G4UniformRand()<.5)
{
theParticleChange.SetMomentumChange(newP->GetMomentumDirection());
theParticleChange.SetEnergyChange(newP->GetKineticEnergy());
delete newP;
G4DynamicParticle* p1 = new G4DynamicParticle;
p1->SetDefinition(targetParticle->GetDefinition());
p1->SetMomentum(targetParticle->GetMomentum());
theParticleChange.AddSecondary(p1);
}
else
{
theParticleChange.SetStatusChange(stopAndKill);
G4DynamicParticle * pA = new G4DynamicParticle;
pA->SetDefinition(targetParticle->GetDefinition());
pA->SetMomentum(newP->GetMomentum());
G4DynamicParticle * pB = new G4DynamicParticle;
pB->SetDefinition(newP->GetDefinition());
pB->SetMomentum(targetParticle->GetMomentum());
delete newP;
theParticleChange.AddSecondary(pA);
theParticleChange.AddSecondary(pB);
}
return &theParticleChange;
}
// end of file
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