Created attachment 837 [details]
eg: my beam.in macro file

I am recently using Geant4 and the “Chem2” example. I ran this example, but it seems that the products of two particles of beam do not interact with each other.

For example, I define two point sources as a gps in the macro file, when I run, they enter the water phantom at the same time and react with its molecules and generate products and other reactions (I made the necessary changes in the PrimaryGeneratorAction files.).

According to the definition of Chem2 example, it seems that both of these particles start from the same initial state that we set in the DetectorConstruction class. Does this mean that these two events, even though they are running at the same time, do not see each other’s effect in the phantom? And Does this make the products of these two particles not react with each other?

I was wondering do some of the primary particles from each particle react with each other? (based on the definition of reactions in the “Chem2” example),
And also for secondary particles, do the defined reactions only happen between the species resulting from a particle? or the secondary products from particle1 can react with secondary products from particle2 (and vice versa)?

I want to know whether the products of two beams interact with each other in Geant4 or not? Is it considered in this example? Is this due to the Geant4 base definition, and is it possible to solve this by adding an algorithm to Geant4 or we should add it to this example? How?