Could not get the results

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_Geant4 Version:_geant4-v11.2.0
_Operating System:_win11
_Compiler/Version:_Visual Studio Version 17.3.5
_CMake Version:_cmake-3.28.1

Hello everyone,

I am currently trying to learn Geant4 and to do this I am studying on a project that bombards the target with gamma rays. I’m trying to find the difference in light intensity between these rays after they hit the target. I do not know what should I have in this project. When I command /run/beamOn 10 simulation suddenly closing and gives no results. Then after closing the window I get

Could not convert to integer: 3221226505. Path ‘exitCode’.
Value was either too large or too small for an In32.

The code that I updated B1 example a little, looks fine but I guess there should be “Track” or “Detector”. In addition the B1 Example code works totally fine.
Plus I use geant4_pybind.

import cmath
from os import environ
from geant4_pybind import *

import sys
import math

class DetectorConstruction(G4VUserDetectorConstruction): 
    def __init__(self):
        self.fScoringVolume = None
    def DefineMaterials(self):
        nist = G4NistManager.Instance()

        isotopes = False
        C = nist.FindOrBuildElement("C", isotopes)
        H = nist.FindOrBuildElement("H", isotopes)
        O = nist.FindOrBuildElement("O", isotopes)
        S = nist.FindOrBuildElement("S", isotopes)

        self.PSU = G4Material("Polysulfone", 1.183*g/cm3)
        self.PSU.AddElement(C, 6)
        self.PSU.AddElement(O, 2)
        self.PSU.AddElement(H, 4)
        self.PSU.AddElement(S, 1)

    def Construct(self):
        nist = G4NistManager.Instance()
        env_sizeXY = 80*cm
        env_sizeZ = 80*cm
        env_mat = nist.FindOrBuildMaterial("G4_AIR")
        targetMaterial = nist.FindOrBuildMaterial("Polysulfone")

        checkOverlaps = True

        world_sizeXY = 1.2*env_sizeXY
        world_sizeZ = 1.2*env_sizeZ
        world_mat = nist.FindOrBuildMaterial("G4_AIR")

        solidWorld = G4Box("World", 0.5*world_sizeXY, 0.5 *
                           world_sizeXY, 0.5*world_sizeZ)
        logicWorld = G4LogicalVolume(solidWorld, world_mat, "World")

        physWorld = G4PVPlacement(None,              # no rotation
                                  G4ThreeVector(),   # at (0,0,0)
                                  logicWorld,        # its logical volume
                                  "World",           # its name
                                  None,              # its mother  volume
                                  False,             # no boolean operation
                                  0,                 # copy number
                                  checkOverlaps)     # overlaps checking

        solidEnv = G4Box("Envelope", 0.5*env_sizeXY,
                         0.5*env_sizeXY, 0.5*env_sizeZ)

        logicEnv = G4LogicalVolume(solidEnv,    # its solid
                                   env_mat,     # its material
                                   "Envelope")  # its name

        G4PVPlacement(None,              # no rotation
                      G4ThreeVector(),   # at (0,0,0)
                      logicEnv,          # its logical volume
                      "Envelope",        # its name
                      logicWorld,        # its mother  volume
                      True,              # no boolean operation
                      0,                 # copy number
                      checkOverlaps)     # overlaps checking

        targetExample = G4Box("Target", 1.0*cm , 5.0*cm, 5.0*cm )

        # Create logical volume
        logic_target = G4LogicalVolume(targetExample, targetMaterial, "Target")

        # Place the cylinder in the world volume
        position = G4ThreeVector(5.0*cm, 0, 0)
        rotation = G4RotationMatrix()
        physical_target = G4PVPlacement(None, position, logic_target, "Target", logicEnv, False, 0, checkOverlaps)

        self.fScoringVolume = logic_target

        return physWorld

class RunAction(G4UserRunAction):
    def __init__(self):
        milligray = 1.e-3*gray
        microgray = 1.e-6*gray
        nanogray = 1.e-9*gray
        picogray = 1.e-12*gray

        G4UnitDefinition("milligray", "milliGy", "Dose", milligray)
        G4UnitDefinition("microgray", "microGy", "Dose", microgray)
        G4UnitDefinition("nanogray", "nanoGy", "Dose", nanogray)
        G4UnitDefinition("picogray", "picoGy", "Dose", picogray)

        self.edep = G4Accumulable(0)
        self.edep2 = G4Accumulable(0)

        accumulableManager = G4AccumulableManager.Instance()

    def BeginOfRunAction(self, aRun):

        accumulableManager = G4AccumulableManager.Instance()

    def EndOfRunAction(self, aRun):
        nofEvents = aRun.GetNumberOfEvent()
        if nofEvents == 0:

        # Merge accumulables
        accumulableManager = G4AccumulableManager.Instance()

        edep = self.edep.GetValue()
        edep2 = self.edep2.GetValue()

        # Compute dose = total energy deposit in a run and its variance
        rms = edep2 - edep*edep/nofEvents
        if rms > 0:
            rms = math.sqrt(rms)
            rms = 0

        detectorConstruction = G4RunManager.GetRunManager().GetUserDetectorConstruction()
        mass = detectorConstruction.fScoringVolume.GetMass()
        dose = edep/mass
        rmsDose = rms/mass

        generatorAction = G4RunManager.GetRunManager().GetUserPrimaryGeneratorAction()
        runCondition = ""
        if generatorAction != None and isinstance(generatorAction, B1PrimaryGeneratorAction):
            particleGun = generatorAction.fParticleGun
            runCondition += particleGun.GetParticleDefinition().GetParticleName() + "(s)"
            runCondition += " of "
            particleEnergy = particleGun.GetParticleEnergy()
            runCondition += "{:.5g}".format(G4BestUnit(particleEnergy, "Energy"))

        if self.IsMaster():
            print("--------------------End of Global Run-----------------------")
            print("--------------------End of Local Run------------------------")

        print(" The run consists of", nofEvents, runCondition)
        print(" Cumulated dose per run, in scoring volume: ", end="")
        print("{:.5f} rms = {:.5f}".format(G4BestUnit(dose, "Dose"), G4BestUnit(rmsDose, "Dose")))

    def AddEdep(self, edep):
        self.edep += edep
        self.edep2 += edep*edep

class EventAction(G4UserEventAction):

    def __init__(self, runAction):
        self.fRunAction = runAction

    def BeginOfEventAction(self, anEvent):
        self.fEdep = 0 

    def EndOfEventAction(self, anEvent):

    def AddEdep(self, edep):
        self.fEdep += edep

class SteppingAction(G4UserSteppingAction):

    def __init__(self, eventAction):
        self.fEventAction = eventAction
        self.fScoringVolume = None

    def UserSteppingAction(self, aStep):
        if self.fScoringVolume == None:
            detectorConstruction = G4RunManager.GetRunManager().GetUserDetectorConstruction()
            self.fScoringVolume = detectorConstruction.fScoringVolume

        volume = aStep.GetPreStepPoint().GetTouchable().GetVolume().GetLogicalVolume()

        # check if we are in scoring volume
        if volume != self.fScoringVolume:

        # collect energy deposited in this step
        edepStep = aStep.GetTotalEnergyDeposit()

class PrimaryGeneratorAction(G4VUserPrimaryGeneratorAction):

    def __init__(self):
        self.fEnvelopeBox = None
        self.fParticleGun = G4ParticleGun(1)

        # default particle kinematic  energy range between 0.1 and 20 MeV
        particleTable = G4ParticleTable.GetParticleTable()
        particle = particleTable.FindParticle("gamma")
        self.fParticleGun.SetParticleMomentumDirection(G4ThreeVector(1, 0, 0))

    def GeneratePrimaries(self, anEvent):
        # this function is called at the begining of each event

        # In order to avoid dependence of PrimaryGeneratorAction
        # on DetectorConstruction class we get Envelope volume
        # from G4LogicalVolumeStore.
        envSizeXY = 0
        envSizeZ = 0
        if self.fEnvelopeBox == None:
            envLV = G4LogicalVolumeStore.GetInstance().GetVolume("Envelope")
            if envLV != None:
                self.fEnvelopeBox = envLV.GetSolid()

        if self.fEnvelopeBox != None:
            envSizeXY = self.fEnvelopeBox.GetXHalfLength()*2
            envSizeZ = self.fEnvelopeBox.GetZHalfLength()*2
            msg = "Envelope volume of box shape not found.\n"
            msg += "Perhaps you have changed geometry.\n"
            msg += "The gun will be place at the center."
                        "MyCode0002", G4ExceptionSeverity.JustWarning, msg)

        size = 0.8
        x0 = size * envSizeXY * (G4UniformRand()-0.5)
        y0 = size * envSizeXY * (G4UniformRand()-0.5)
        z0 = -0.5 * envSizeZ

        self.fParticleGun.SetParticlePosition(G4ThreeVector(x0, y0, z0))

class ActionInitialization(G4VUserActionInitialization):

    def BuildForMaster(self):

    def Build(self):

        runAction = RunAction()

        eventAction = EventAction(runAction)


ui = None
if len(sys.argv) == 1:
    ui = G4UIExecutive(len(sys.argv), sys.argv)

# Optionally: choose a different Random engine...
# G4Random.setTheEngine(MTwistEngine())

runManager = G4RunManagerFactory.CreateRunManager(G4RunManagerType.Serial)


# Physics list
physicsList = QBBC()


# User action initialization

visManager = G4VisExecutive()
# G4VisExecutive can take a verbosity argument - see /vis/verbose guidance.
# visManager = G4VisExecutive("Quiet")

# Get the User Interface manager
UImanager = G4UImanager.GetUIpointer()

# # Process macro or start UI session
if ui == None:
    # batch mode
    command = "/control/execute "
    fileName = sys.argv[1]
    # interactive mode
    UImanager.ApplyCommand("/control/execute init_vis.mac")

I do not know, should I have “Envelope”? How to collect results?

It may be better to address this to the geant4_pybind Issue tracker. Whilst we can offer some general guidance, this is a third party project so we can’t offer support like we can for the C++ interface.

As far as I know, geant4_pybind should offer all the core interfaces needed (but see the caveat in its README), so the Application Developer Guide is still relevant here, albeit you’ll need to translate from C++ to Python.

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