Hi everyone,I should simulate a multitarget system. i.e. currently I’ve a single carbon target 6cm thikness.
// Envelope parameters
//
G4double env_sizeXY = 20*cm, env_sizeZ = 6*cm;
G4Material* env_mat = nist->FindOrBuildMaterial("G4_GRAPHITE");
I would like to simulate a multitarget system (for example 5 targets 0.5 cm thikness spaced 0.5 cm).
How can I add more targets in my code?
Thanks
Hello Faca,
You can do this in a few different ways that are shown in some examples… But one simple way is to use a for loop over the G4PVPlacement function. If j is your iterator, make sure you put j + 1 in the copy input. There are some examples as such in advanced.
Best,
Paul
Hi @marmolRBG, thank you for your reply. This is my G4PVPlacement function in my B1 example:
G4VPhysicalVolume* physWorld =
new G4PVPlacement(0, //no rotation
G4ThreeVector(), //at (0,0,0)
logicWorld, //its logical volume
"World", //its name
0, //its mother volume
false, //no boolean operation
0, //copy number
checkOverlaps); //overlaps checking
I found this code in the amsEcal advanced example:
for (G4int k=0; k<nbOfLayers; k++) {
Xcenter += layerThickness;
Ycenter = - Ycenter;
new G4PVPlacement(0, //no rotation
G4ThreeVector(Xcenter,Ycenter,0.), //position
lvol_layer, //logical volume
"layer", //name
lvol_module, //mother
false, //no boulean operat
k+1); //copy number
}
So, to get 5 targets, I wrote
for (G4int k=0; k<5; k++) {
G4VPhysicalVolume* physWorld =
new G4PVPlacement(0, //no rotation
G4ThreeVector(), //at (0,0,0)
logicWorld, //its logical volume
"World", //its name
0, //its mother volume
false, //no boolean operation
k+1, //copy number
checkOverlaps); //overlaps checking
}
but I get the error in the printscreen. In italian, it means that physWorld isn’t declared, but isnt’t it declared in this line
G4VPhysicalVolume* physWorld
Moreover, withoud the for cycle, it works…
Hi,
I think you need to check the “return” part, it seems “physWorld” should be return to “Construct” in the geometry setting. If you put “G4VPhysicalVolume* physWorld” in the your loop scope, it will show this error.
Hope this is helpful for you.
Cheers,
Ye
Hi @ychen871027, you are right there was
return physWorld
at the end of the code, so I added it in the for cycle in this way
for (G4int k=0; k<5; k++) {
G4VPhysicalVolume* physWorld =
new G4PVPlacement(0, //no rotation
G4ThreeVector(), //at (0,0,0)
logicWorld, //its logical volume
"World", //its name
0, //its mother volume
false, //no boolean operation
k+1, //copy number
checkOverlaps); //overlaps checking
return physWorld;
}
But I fot this warning (it means theare are some paths not returning values!
The I saw there is one other function in which there is the G4VPhysicalVolume and it is
G4LogicalVolume* logicEnv =
new G4LogicalVolume(solidEnv, //its solid
env_mat, //its material
"Envelope"); //its name
new G4PVPlacement(0, //no rotation
G4ThreeVector(), //at (0,0,0)
logicEnv, //its logical volume
"Envelope", //its name
logicWorld, //its mother volume
false, //no boolean operation
0, //copy number
checkOverlaps); //overlaps checking
so I putted it in a for cycle too in this way
new G4Box("Envelope", //its name
0.5*env_sizeXY, 0.5*env_sizeXY, 0.5*env_sizeZ); //its size
G4LogicalVolume* logicEnv =
new G4LogicalVolume(solidEnv, //its solid
env_mat, //its material
"Envelope"); //its name
for (G4int j=0; j<5; j++) {
new G4PVPlacement(0, //no rotation
G4ThreeVector(), //at (0,0,0)
logicEnv, //its logical volume
"Envelope", //its name
logicWorld, //its mother volume
false, //no boolean operation
j+1, //copy number
checkOverlaps); //overlaps checking
}
But I also get a warning
I add the B1DetectorConstruction.c file
B1DetectorConstruction.cc (9.4 KB)
Hi,
If you put that into your loop scope, you will be trying to return multiple world.
It is meaningless.
The geometry construction is like below.
The following link shows how to create a calorimeter.
Cheers,
Ye
Hi @ychen871027, thank you for your reply. Unfortunately I can’t understand how to adapt your code in mine (I’m a new user). Please, can you write some note in my code, in order to understand?
