G4ChemDissociationChannels.cc

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// Geant4 class G4ChemDissociationChannels
//
// Author H. Tran 16.12.2022
//
 
#include "G4ChemDissociationChannels.hh"
 
#include "G4DNAWaterDissociationDisplacer.hh"
#include "G4DNAWaterExcitationStructure.hh"
#include "G4Electron_aq.hh"
#include "G4H2.hh"
#include "G4H2O.hh"
#include "G4H2O2.hh"
#include "G4H3O.hh"
#include "G4Hydrogen.hh"
#include "G4MolecularConfiguration.hh"
#include "G4MoleculeTable.hh"
#include "G4OH.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
void G4ChemDissociationChannels::ConstructMolecule()
{
  // Create the definition
  G4H2O::Definition();
  G4Hydrogen::Definition();
  G4H3O::Definition();
  G4OH::Definition();
  G4Electron_aq::Definition();
  G4H2O2::Definition();
  G4H2::Definition();
  auto molTable = G4MoleculeTable::Instance();
 
  molTable->CreateConfiguration("H3Op", G4H3O::Definition());
  G4MolecularConfiguration* OHm =
    molTable->CreateConfiguration("OHm",  // just a tag to store and retrieve
                                                             // from G4MoleculeTable
      G4OH::Definition(),
      -1,  // charge
      5.0e-9 * (m2 / s));
  OHm->SetMass(17.0079 * g / Avogadro * c_squared);
  molTable->CreateConfiguration("OH", G4OH::Definition());
  molTable->CreateConfiguration("e_aq", G4Electron_aq::Definition());
  molTable->CreateConfiguration("H", G4Hydrogen::Definition());
  molTable->CreateConfiguration("H2", G4H2::Definition());
  molTable->CreateConfiguration("H2O2", G4H2O2::Definition());
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
void G4ChemDissociationChannels::ConstructDissociationChannels()
{
  //-----------------------------------
  // Get the molecular configuration
  auto molTable = G4MoleculeTable::Instance();
  G4MolecularConfiguration* OH = molTable->GetConfiguration("OH");
  G4MolecularConfiguration* OHm = molTable->GetConfiguration("OHm");
  G4MolecularConfiguration* e_aq = molTable->GetConfiguration("e_aq");
  G4MolecularConfiguration* H2 = molTable->GetConfiguration("H2");
  G4MolecularConfiguration* H3O = molTable->GetConfiguration("H3Op");
  G4MolecularConfiguration* H = molTable->GetConfiguration("H");
 
  //-------------------------------------
  // Define the decay channels
  G4MoleculeDefinition* water = G4H2O::Definition();
  G4MolecularDissociationChannel* decCh1;
  G4MolecularDissociationChannel* decCh2;
 
  auto occ = new G4ElectronOccupancy(*(water->GetGroundStateElectronOccupancy()));
 
  //////////////////////////////////////////////////////////
  //            EXCITATIONS                               //
  //////////////////////////////////////////////////////////
  G4DNAWaterExcitationStructure waterExcitation;
  //--------------------------------------------------------
  //---------------Excitation on the fifth layer------------
 
  decCh1 = new G4MolecularDissociationChannel("A^1B_1_Relax");
  decCh2 = new G4MolecularDissociationChannel("A^1B_1_DissociDecay");
  // Decay 1 : OH + H
  decCh1->SetEnergy(waterExcitation.ExcitationEnergy(0));
  decCh1->SetProbability(0.35);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::NoDisplacement);
 
  decCh2->AddProduct(OH);
  decCh2->AddProduct(H);
  decCh2->SetProbability(0.65);
  decCh2->SetDisplacementType(G4DNAWaterDissociationDisplacer::A1B1_DissociationDecay);
 
  //  water->AddExcitedState("A^1B_1");
  occ->RemoveElectron(4, 1);  // this is the transition form ground state to
  occ->AddElectron(5, 1);  // the first unoccupied orbital: A^1B_1
 
  water->NewConfigurationWithElectronOccupancy("A^1B_1", *occ);
  water->AddDecayChannel("A^1B_1", decCh1);
  water->AddDecayChannel("A^1B_1", decCh2);
 
  //--------------------------------------------------------
  //---------------Excitation on the fourth layer-----------
  decCh1 = new G4MolecularDissociationChannel("B^1A_1_Relax_Channel");
  decCh2 = new G4MolecularDissociationChannel("B^1A_1_DissociDecay");
  auto decCh3 = new G4MolecularDissociationChannel("B^1A_1_AutoIoni_Channel");
 
  // Decay 1 : energy
  decCh1->SetEnergy(waterExcitation.ExcitationEnergy(1));
  decCh1->SetProbability(0.3);
 
  // Decay 2 : 2OH + H_2
  decCh2->AddProduct(H2);
  decCh2->AddProduct(OH);
  decCh2->AddProduct(OH);
  decCh2->SetProbability(0.15);
  decCh2->SetDisplacementType(G4DNAWaterDissociationDisplacer::B1A1_DissociationDecay);
 
  // Decay 3 : OH + H_3Op + e_aq
  decCh3->AddProduct(OH);
  decCh3->AddProduct(H3O);
  decCh3->AddProduct(e_aq);
  decCh3->SetProbability(0.55);
  decCh3->SetDisplacementType(G4DNAWaterDissociationDisplacer::AutoIonisation);
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(3);  // this is the transition form ground state to
  occ->AddElectron(5, 1);  // the first unoccupied orbital: B^1A_1
 
  water->NewConfigurationWithElectronOccupancy("B^1A_1", *occ);
  water->AddDecayChannel("B^1A_1", decCh1);
  water->AddDecayChannel("B^1A_1", decCh2);
  water->AddDecayChannel("B^1A_1", decCh3);
 
  //-------------------------------------------------------
  //-------------------Excitation of 3rd layer-----------------
  decCh1 = new G4MolecularDissociationChannel("Exc3rdLayer_AutoIoni_Channel");
  decCh2 = new G4MolecularDissociationChannel("Exc3rdLayer_Relax_Channel");
 
  // Decay channel 1 : : OH + H_3Op + e_aq
  decCh1->AddProduct(OH);
  decCh1->AddProduct(H3O);
  decCh1->AddProduct(e_aq);
 
  decCh1->SetProbability(0.5);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::AutoIonisation);
 
  // Decay channel 2 : energy
  decCh2->SetEnergy(waterExcitation.ExcitationEnergy(2));
  decCh2->SetProbability(0.5);
 
  // Electronic configuration of this decay
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(2, 1);
  occ->AddElectron(5, 1);
 
  // Configure the water molecule
  water->NewConfigurationWithElectronOccupancy("Exci3rdLayer", *occ);
  water->AddDecayChannel("Exci3rdLayer", decCh1);
  water->AddDecayChannel("Exci3rdLayer", decCh2);
 
  //-------------------------------------------------------
  //-------------------Excitation of 2nd layer-----------------
  decCh1 = new G4MolecularDissociationChannel("Exc2ndLayer_AutoIoni_Channel");
  decCh2 = new G4MolecularDissociationChannel("Exc2ndLayer_Relax_Channel");
 
  // Decay Channel 1 : : OH + H_3Op + e_aq
  decCh1->AddProduct(OH);
  decCh1->AddProduct(H3O);
  decCh1->AddProduct(e_aq);
 
  decCh1->SetProbability(0.5);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::AutoIonisation);
 
  // Decay channel 2 : energy
  decCh2->SetEnergy(waterExcitation.ExcitationEnergy(3));
  decCh2->SetProbability(0.5);
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(1, 1);
  occ->AddElectron(5, 1);
 
  water->NewConfigurationWithElectronOccupancy("Exci2ndLayer", *occ);
  water->AddDecayChannel("Exci2ndLayer", decCh1);
  water->AddDecayChannel("Exci2ndLayer", decCh2);
 
  //-------------------------------------------------------
  //-------------------Excitation of 1st layer-----------------
  decCh1 = new G4MolecularDissociationChannel("Exci1stLayer_AutoIoni_Channel");
  decCh2 = new G4MolecularDissociationChannel("Exci1stLayer_Relax_Channel");
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(0, 1);
  occ->AddElectron(5, 1);
 
  // Decay Channel 1 : : OH + H_3Op + e_aq
  decCh1->AddProduct(OH);
  decCh1->AddProduct(H3O);
  decCh1->AddProduct(e_aq);
  decCh1->SetProbability(0.5);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::AutoIonisation);
 
  // Decay channel 2 : energy
  decCh2->SetEnergy(waterExcitation.ExcitationEnergy(4));
  decCh2->SetProbability(0.5);
 
  water->NewConfigurationWithElectronOccupancy("Exci1stLayer", *occ);
  water->AddDecayChannel("Exci1stLayer", decCh1);
  water->AddDecayChannel("Exci1stLayer", decCh2);
 
  /////////////////////////////////////////////////////////
  //                  IONISATION                         //
  /////////////////////////////////////////////////////////
  //--------------------------------------------------------
  //------------------- Ionisation -------------------------
 
  decCh1 = new G4MolecularDissociationChannel("Ioni_Channel");
 
  // Decay Channel 1 : : OH + H_3Op
  decCh1->AddProduct(H3O);
  decCh1->AddProduct(OH);
  decCh1->SetProbability(1);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::Ionisation_DissociationDecay);
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(4, 1);
  // this is a ionized h2O with a hole in its last orbital
  water->NewConfigurationWithElectronOccupancy("Ioni5", *occ);
  water->AddDecayChannel("Ioni5", decCh1);
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(3, 1);
  water->NewConfigurationWithElectronOccupancy("Ioni4", *occ);
  water->AddDecayChannel("Ioni4", new G4MolecularDissociationChannel(*decCh1));
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(2, 1);
  water->NewConfigurationWithElectronOccupancy("Ioni3", *occ);
  water->AddDecayChannel("Ioni3", new G4MolecularDissociationChannel(*decCh1));
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(1, 1);
  water->NewConfigurationWithElectronOccupancy("Ioni2", *occ);
  water->AddDecayChannel("Ioni2", new G4MolecularDissociationChannel(*decCh1));
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->RemoveElectron(0, 1);
  water->NewConfigurationWithElectronOccupancy("Ioni1", *occ);
  water->AddDecayChannel("Ioni1", new G4MolecularDissociationChannel(*decCh1));
 
  //////////////////////////////////////////////////////////
  //            Dissociative Attachment                   //
  //////////////////////////////////////////////////////////
  decCh1 = new G4MolecularDissociationChannel("DissociAttachment");
 
  // Decay 1 : 2OH + H_2
  decCh1->AddProduct(H2);
  decCh1->AddProduct(OHm);
  decCh1->AddProduct(OH);
  decCh1->SetProbability(1);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::DissociativeAttachment);
 
  *occ = *(water->GetGroundStateElectronOccupancy());
  occ->AddElectron(5, 1);  // H_2O^-
  water->NewConfigurationWithElectronOccupancy("DissociAttachment", *occ);
  water->AddDecayChannel("DissociAttachment", decCh1);
 
  //////////////////////////////////////////////////////////
  //            Electron-hole recombination               //
  //////////////////////////////////////////////////////////
  decCh1 = new G4MolecularDissociationChannel("H2Ovib_DissociDecay1");
  decCh2 = new G4MolecularDissociationChannel("H2Ovib_DissociDecay2");
  decCh3 = new G4MolecularDissociationChannel("H2Ovib_DissociDecay3");
 
  // Decay 1 : 2OH + H_2
  decCh1->AddProduct(H2);
  decCh1->AddProduct(OH);
  decCh1->AddProduct(OH);
  decCh1->SetProbability(0.15);
  decCh1->SetDisplacementType(G4DNAWaterDissociationDisplacer::B1A1_DissociationDecay);
 
  // Decay 2 : OH + H
  decCh2->AddProduct(OH);
  decCh2->AddProduct(H);
  decCh2->SetProbability(0.55);
  decCh2->SetDisplacementType(G4DNAWaterDissociationDisplacer::A1B1_DissociationDecay);
 
  // Decay 3 : relaxation
  decCh3->SetProbability(0.30);
 
  const auto pH2Ovib = G4H2O::Definition()->NewConfiguration("H2Ovib");
  water->AddDecayChannel(pH2Ovib, decCh1);
  water->AddDecayChannel(pH2Ovib, decCh2);
  water->AddDecayChannel(pH2Ovib, decCh3);
 
  delete occ;
}