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26 // $Id: G4IonParametrisedLossModel.icc 66241 2012-12-13 18:34:42Z gunter $
28 // ===========================================================================
31 // Class: G4IonParametrisedLossModel
33 // Base class: G4VEmModel (utils)
35 // Author: Anton Lechner (Anton.Lechner@cern.ch)
37 // First implementation: 10. 11. 2008
39 // Modifications: 03. 02. 2009 - Bug fix iterators (AL)
40 // 11. 03. 2009 - Introduced new table handler (G4IonDEDXHandler)
41 // and modified method to add/remove tables
42 // (tables are now built in initialisation phase),
43 // Minor bug fix in ComputeDEDXPerVolume (AL)
44 // 20. 11. 2009 - Added set-method for energy loss limit (AL)
45 // 04. 11. 2010 - Moved virtual methods to the source (VI)
48 // Model for computing the energy loss of ions by employing a
49 // parameterisation of dE/dx tables (default ICRU 73 tables). For
50 // ion-material combinations and/or projectile energies not covered
51 // by this model, the G4BraggIonModel and G4BetheBloch models are
56 // ===========================================================================
58 inline G4double G4IonParametrisedLossModel::DeltaRayMeanEnergyTransferRate(
59 const G4Material* material,
60 const G4ParticleDefinition* particle,
61 G4double kineticEnergy,
64 // ############## Mean energy transferred to delta-rays ###################
65 // Computes the mean energy transfered to delta-rays per unit length,
66 // considering only delta-rays with energies above the energy threshold
69 // The mean energy transfer rate is derived by using the differential
70 // cross section given in the references below.
72 // See Geant4 physics reference manual (version 9.1), section 9.1.3
74 // Ref.: W.M. Yao et al, Jour. of Phys. G 33 (2006) 1.
75 // B. Rossi, High energy particles, New York, NY: Prentice-Hall (1952).
77 // (Implementation adapted from G4BraggIonModel)
81 // kineticEnergy = kinetic energy of projectile
82 // totEnergy = total energy of projectile, i.e. kinetic energy
83 // plus rest energy (Mc^2)
84 // betaSquared = beta of projectile squared, calculated as
85 // beta^2 = 1 - 1 / (E/Mc^2)^2
86 // = T * ( E + Mc^2 ) / E^2
87 // where T = kineticEnergy, E = totEnergy
88 // cutEnergy = energy threshold for secondary particle production
89 // i.e. energy cut, below which energy transfered to
90 // electrons is treated as continuous loss of projectile
91 // maxKinEnergy = maximum energy transferable to secondary electrons
92 // meanRate = mean kinetic energy of delta ray (per unit length)
95 G4double meanRate = 0.0;
97 G4double maxKinEnergy = MaxSecondaryEnergy(particle, kineticEnergy);
99 if (cutEnergy < maxKinEnergy) {
101 G4double totalEnergy = kineticEnergy + cacheMass;
102 G4double betaSquared = kineticEnergy *
103 (totalEnergy + cacheMass) / (totalEnergy * totalEnergy);
105 G4double cutMaxEnergyRatio = cutEnergy / maxKinEnergy;
108 (- std::log(cutMaxEnergyRatio) - (1.0 - cutMaxEnergyRatio) * betaSquared) *
109 CLHEP::twopi_mc2_rcl2 *
110 (material->GetTotNbOfElectPerVolume()) / betaSquared;
112 meanRate *= GetChargeSquareRatio(particle, material, kineticEnergy);
119 void G4IonParametrisedLossModel::UpdateCache(
120 const G4ParticleDefinition* particle) {
122 cacheParticle = particle;
123 cacheMass = particle -> GetPDGMass();
124 cacheElecMassRatio = CLHEP::electron_mass_c2 / cacheMass;
125 G4double q = particle -> GetPDGCharge() / CLHEP::eplus;
126 cacheChargeSquare = q * q;
130 LossTableList::iterator G4IonParametrisedLossModel::IsApplicable(
131 const G4ParticleDefinition* particle, // Projectile (ion)
132 const G4Material* material) { // Target material
134 LossTableList::iterator iter = lossTableList.end();
135 LossTableList::iterator iterTables = lossTableList.begin();
136 LossTableList::iterator iterTables_end = lossTableList.end();
138 for(;iterTables != iterTables_end; iterTables++) {
139 G4bool isApplicable = (*iterTables) ->
140 IsApplicable(particle, material);
152 void G4IonParametrisedLossModel::SetEnergyLossLimit(
153 G4double ionEnergyLossLimit) {
155 if(ionEnergyLossLimit > 0 && ionEnergyLossLimit <=1) {
157 energyLossLimit = ionEnergyLossLimit;