A warning with Variance reduction MC mode in RadioDecay

Physics Processes, Models and Cross Sections
1

Information for Geant4

  • Geant4 Version: Geant4.11.2.0-beta
  • Operating System: MacOS Sonoma 14.0
  • Compiler/Version: AppleClang 15.0.0
  • CMake Version: 3.26.5

Problem

If the /process/had/rdm/analogueMC false was used, the error came as following:

  • [1] 95582 segmentation fault ./Am gps.mac > 1.log
  • G4SeltzerBergerModel Warning: Majoranta exceeded! 2.11759 > 1.9996 by 1.05901 Niter= 0 Egamma(MeV)= 0.31837 Ee(MeV)= 0.318912 Z= 95 e-

Code

DetectorConstruction.cc

G4VPhysicalVolume* DetectorConstruction::Construct() {
    // Define Materials
    auto nist_manager = G4NistManager::Instance();
    G4Material *world_mat = nist_manager->FindOrBuildMaterial("G4_AIR");
    
    G4Isotope *Am_243_iso = new G4Isotope("Am243", 95, 243, 243.06138*g/mole); 
    G4Element *elAm = new G4Element("AmericiumElement", "Am", 1); 
    elAm->AddIsotope(Am_243_iso, 100.*perCent);
    G4double density_Am243 = 13.67 * g/cm3;  
    G4Material* Am_243 = new G4Material("Am_243", density_Am243, 1);
    Am_243->AddElement(elAm, 100.*perCent);

    // Define World
    G4double world_length = 10 * cm;
    auto world_solid = new G4Box("World_Solid", world_length/2, world_length/2, world_length/2);
    auto world_logic = new G4LogicalVolume(world_solid, world_mat, "World_logic");
    G4VPhysicalVolume* world_phys = new G4PVPlacement(nullptr, G4ThreeVector(), world_logic, "World_Phys", nullptr, false, 0, true);

    // Define Am-243
    G4double source_length = 200 * um;
    auto source_solid = new G4Box("Source_Solid", source_length/2, source_length/2, source_length/2);
    auto source_logic = new G4LogicalVolume(source_solid, Am_243, "Source_Logic");
    new G4PVPlacement(nullptr, G4ThreeVector(), source_logic, "Source_Phys", world_logic, false, 0, true);

    return world_phys;

}

PhysicsList.cc

PhysicsList::PhysicsList() : G4VModularPhysicsList() {
    // 1. Verbose
    SetVerboseLevel(1);

    G4NuclideTable::GetInstance()->SetThresholdOfHalfLife(0.1*picosecond);
    G4NuclideTable::GetInstance()->SetLevelTolerance(1.0*eV);

    RegisterPhysics(new G4EmLivermorePhysics());
    G4EmParameters* param = G4EmParameters::Instance();
    param->SetAugerCascade(true);
    param->SetDeexcitationIgnoreCut(true);    
    param->SetStepFunction(1., 1*CLHEP::mm); // for e- and e+ 
    param->SetStepFunctionMuHad(1., 1*CLHEP::mm);  
    /*
    * RegisterPhysics(new G4EmStandardPhysics());
    * G4EmParameters* param = G4EmParameters::Instance();
    * param->SetAugerCascade(true);
    * param->SetStepFunction(1., 1*CLHEP::mm);
    * param->SetStepFunctionMuHad(1., 1*CLHEP::mm);
    */
    RegisterPhysics(new G4DecayPhysics());
    RegisterPhysics(new BiasedRDPhysics()); 
    RegisterPhysics(new G4HadronPhysicsQGSP_BIC());
    RegisterPhysics(new G4HadronElasticPhysics());
    RegisterPhysics( new G4IonElasticPhysics());  
    RegisterPhysics( new G4IonPhysics());
    G4EmExtraPhysics* gnuc = new G4EmExtraPhysics();
    gnuc->ElectroNuclear(false);
    gnuc->MuonNuclear(false);
    RegisterPhysics(gnuc);
    cut_value = 1 * um;
    SetDefaultCutValue(cut_value);
}

mac file

/run/initialize
/process/had/rdm/noVolumes
/process/had/rdm/selectVolume Source_Logic

#/process/had/rdm/nucleusLimits 243 243 95 95
/gps/particle ion 
/gps/ion 95 243
/gps/energy 0
/process/had/rdm/analogueMC false

/gps/pos/type Volume
/gps/pos/shape Para
/gps/pos/halfx 100 um
/gps/pos/halfy 100 um
/gps/pos/halfz 100 um
/gps/pos/centre 0 0 0 um
/gps/ang/type iso

/run/beamOn 10000

Debug

The lldb was used with lldb ./Am, and in the lldb r gps.mac.Then the code with bt was used to trace the error, and the result was following:

image
image1740×820 254 KB

How to solve it? And if the “Analogue mode” was used, there is no error!
Thanks for your help!
Best!
Kun ZHU