Gabriele Cosmo
274 lines
6.3 KiB
C++
274 lines
6.3 KiB
C++
// This code implementation is the intellectual property of
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// the GEANT4 collaboration.
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//
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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 statement,
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// and all its terms.
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//
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//
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// --------------------------------------------------------------
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// GEANT 4 class implementation file --- Copyright CERN 1998
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// CERN Geneva Switzerland
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//
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// File: G4StopElementSelector
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//
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// Author: V.Ivanchenko (Vladimir.Ivanchenko@cern.ch)
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//
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// Creation date: 2 April 2000
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//
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// Class Description:
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//
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// Selection of elements for negative particle cupture
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// Selection between decay/capture for mu-
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// N.C.Mukhopadhyay Phys. Rep. 30 (1977) 1.
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//
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// Class Description: End
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//
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//-----------------------------------------------------------------------------
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//
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// Modifications:
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// 18/08/2000 V.Ivanchenko Update description
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//
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//-----------------------------------------------------------------------------
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#include "G4StopElementSelector.hh"
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#include "g4std/vector"
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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// constructor
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G4StopElementSelector::G4StopElementSelector()
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{ }
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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// destructor
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G4StopElementSelector::~G4StopElementSelector()
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{ }
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4Element* G4StopElementSelector::GetElement(const G4Material* aMaterial)
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{
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// Fermi-Teller Z-low of mu- capture and exceptions
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// for halogens and oxigen.
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// N.C.Mukhopadhyay Phys. Rep. 30 (1977) 1.
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G4int i;
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G4double Z;
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const G4int numberOfElements = aMaterial->GetNumberOfElements();
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const G4ElementVector* theElementVector = aMaterial->GetElementVector();
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if(1 == numberOfElements) return (*theElementVector)(0);
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const G4double* theAtomicNumberDensity = aMaterial->GetAtomicNumDensityVector();
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G4double sum = 0.0;
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for ( i=0; i < numberOfElements; i++ ) {
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Z = (*theElementVector)(i)->GetZ();
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// Halogens
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if( (9.0 == Z) || (17.0 == Z) || (35.0 == Z) || (53.0 == Z) || (85.0 == Z) ) {
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sum += 0.66 * Z * theAtomicNumberDensity[i] ;
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// Oxigen
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} else if( 8.0 == Z ) {
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sum += 0.56 * Z * theAtomicNumberDensity[i] ;
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// Others
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} else {
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sum += Z * theAtomicNumberDensity[i] ;
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}
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}
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G4double random = G4UniformRand() * sum;
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sum = 0.0 ;
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i = -1;
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// Selection of element
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do {
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i++;
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Z = (*theElementVector)(i)->GetZ();
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// Galogens
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if( (9.0 == Z) || (17.0 == Z) || (35.0 == Z) || (53.0 == Z) || (85.0 == Z) ) {
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sum += 0.66 * Z * theAtomicNumberDensity[i] ;
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// Oxigen
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} else if( 8.0 == Z ) {
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sum += 0.56 * Z * theAtomicNumberDensity[i] ;
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// Others
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} else {
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sum += Z * theAtomicNumberDensity[i] ;
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}
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} while ( (sum < random) && (i < numberOfElements - 1) );
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return (*theElementVector)(i);
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4StopElementSelector::GetMuonCaptureRate(G4double Z, G4double A)
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{
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// Initialized data
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// static G4std::vector<G4double> zeff(100);
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static G4double zeff[100] = {
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1.,1.98,2.95,3.89,4.8,5.72,6.61,7.49,8.32,9.12,9.95,10.69,11.48,12.22,
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12.91,13.64,14.24,14.89,15.53,16.15,16.75,17.38,18.04,18.49,
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19.06,19.59,20.1,20.66,21.12,21.61,22.02,22.43,22.84,23.24,
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23.65,24.06,24.47,24.85,25.23,25.61,25.99,26.37,26.69,27.,
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27.32,27.63,27.95,28.2,28.42,28.64,28.79,29.03,29.27,29.51,
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29.75,29.99,30.2,30.36,30.53,30.69,30.85,31.01,31.18,31.34,
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31.48,31.62,31.76,31.9,32.05,32.19,32.33,32.47,32.61,32.76,
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32.94,33.11,33.29,33.46,33.64,33.81,34.21,34.18,34.,34.1,
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34.21,34.31,34.42,34.52,34.63,34.73,34.84,34.94,35.04,35.15,
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35.25,35.36,35.46,35.57,35.67,35.78 };
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// Mu- capture data from B.B.Balashov, G.Ya.Korenman, P.A.Eramgan
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// Atomizdat, 1978. (Experimental capture velocities)
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const size_t ListZE = 65;
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// static G4std::vector<G4int> ListZExp[ListZE] = {
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static G4int ListZExp[ListZE] = {
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3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
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13, 14, 15, 16, 17, 18, 19, 20, 22, 23,
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24, 25, 26, 27, 28, 31, 32, 33, 34, 37,
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38, 39, 40, 41, 42, 45, 46, 47, 48, 49,
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50, 51, 52, 53, 55, 56, 57, 58, 59, 60,
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62, 64, 65, 67, 72, 73, 74, 80, 81, 82,
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83, 90, 92, 93};
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// static G4std::vector<G4double> ListCaptureVel[ListZE] = {
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static G4double ListCaptureVel[ListZE] = {
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0.0057, 0.010, 0.0258, 0.0371, 0.0644,
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0.0974, 0.144, 0.250, 0.386, 0.479,
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0.700, 0.849, 1.119, 1.338, 1.40,
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1.30, 1.98, 2.45, 2.60, 3.19,
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3.29, 3.91, 4.41, 4.96, 5.74,
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5.68, 5.53, 6.06, 5.69, 6.89,
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7.25, 7.89, 8.59, 10.40, 9.22,
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10.01, 10.00, 10.88, 10.62, 11.37,
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10.68, 10.49, 9.06, 11.20, 10.98,
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10.18, 10.71, 11.44, 13.45, 12.32,
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12.22, 12.09, 12.73, 12.95, 13.03,
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12.86, 13.13, 13.39, 12.74, 13.78,
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13.02, 13.26, 13.10, 14.00, 14.70};
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// Local variables
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G4double zeff2, xmu, a2ze, r1, r2;
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G4double lambda;
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// == Effective charges from Ford and Wills Nucl Phys 35(1962)295.
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// == Untabulated charges are interpolated.
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// == Mu capture lifetime (Goulard and Primakoff PRC10(1974)2034.
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G4int i = G4int(Z) - 1 ;
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if(i > 99) i = 99;
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const G4double b0a = -.03;
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const G4double b0b = -.25;
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const G4double b0c = 3.24;
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const G4double t1 = 875.e-10;
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r1 = zeff[i];
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zeff2 = r1 * r1;
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xmu = zeff2 * 2.663e-4;
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a2ze = 0.5 * A / Z;
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r2 = 1.0 - xmu;
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lambda = t1 * zeff2 * zeff2 * (r2 * r2) * (1.0 - (1.0 - xmu) * .75704) *
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(a2ze * b0a + 1.0 - (a2ze - 1.0) * b0b -
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(2.0 * (A - Z) / Z + abs(a2ze - 1.) ) * b0c / (A * 4.) );
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// == Mu capture data are taken if exist
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for (G4int j = 0; j < ListZE; j++) {
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if( ListZExp[j] == i + 1) {
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lambda = ListCaptureVel[j] / microsecond;
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break;
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}
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}
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return lambda;
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}
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//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
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G4double G4StopElementSelector::GetMuonDecayRate(G4double Z, G4double A)
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{
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// Decay time on K-shell
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// N.C.Mukhopadhyay Phys. Rep. 30 (1977) 1.
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G4double lambda = 1.0 - 2.5 * Z * Z / (137.0*137.0);
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if( 0.5 > lambda ) lambda = 0.5;
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return lambda * 0.445 / microsecond;
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}
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