Core dump while creating World box within specific size

Getting Started
1

Hello,

I am new to Geant4 and encountered a problem while creating a world box within specific size.
What i did was copying the basic example B1 from the main folder and pasting to another folder, deleting all the elements of the Construct() function inside B1DetectorConstruction.cc, and trying to create a new model.

Below is the world box i was trying to create.

G4Box * world  	 = new G4Box("world", 15* um, 15* um, 2000 * um );
G4Material* Air    = nist->FindOrBuildMaterial("G4_AIR");
G4LogicalVolume* lworld   = new G4LogicalVolume(world, Air, "world");
G4VPhysicalVolume* pworld = new G4PVPlacement(0, G4ThreeVector(), lworld,
                                              "world", 0, false, 0, false);
return pworld;

The build process ended successfully. The “make” process inside the build folder was also successful, but when i tried to execute the ./exampleB1 , I always got a “core dump”.
This error does not occur when the unit is changed to e.g., 15 cm, or if the size is smaller e.g., 15 nm.
I tried to avoid the error by using 15 * 1000 * nm, but it also didn’t work.

I didn’t get any error message at all and have been trying to solve the problem for couple hours, yet can’t think of any solution.
Is there any configuration elsewhere that i perhaps have to set, to make the size works?

I would really appreciate for tips and help for this matter

Thank you,
Jay

p.s.: am using Geant4 10.5

2

did you change anything in the examples/basic/B1/src/B1PrimaryGeneratorAction.cc · geant4-10.5-release · geant4 / geant4 · GitLab?

3

No, i did not change anything else beside the Construct() in B1DetectorConstructor.
I just took it raw from the basic example folder, and modified the Construct().

4

perhaps you could try to make some adjustments there, such that the particles are all created at the origin?

As I understand, particle positions are randomly sampled depending on some envelope. This way you could eliminate this, and see if that helps.
As I further understand, the random engine is deterministically seeded, hence, the core dump is also reproduced reliably.

5

That’s a nice tips!
I will try to do it first.

Thank you

6

Update:

I have tried to set the particle gun to be placed on the 0,0,0
fParticleGun->SetParticlePosition(G4ThreeVector(0,0,0));

and set the particle to move in Z direction
fParticleGun->SetParticleMomentumDirection(G4ThreeVector(1.,0.,1.));

to ensure that the particle is shot within the “World” range.

I’ve also tried to look for another files within src folders, hoping to find some clue where i might screwed up, or perhaps found some missing configuration.
But i didn’t find any configuration, that stated that i cant use that specific world size.

Does anyone perhaps have the same problem as mine?

Any further help or response would be much appreciated

Thank you,
Jay