when i Assign SD to the logical volume i find this error
can you help me to fix it please.
Looks like Box_Hall is not a member of your DetectorConstruction class.
Do you only define it in DetectorConstruction::Construct()?
Yes it’s defined only in construct.
Then that is your issue. The function ConstructSDandField() does not know about Box_Hall because it only exists in Contruct()
Checkout examples/basic/B5