I have previously presented my simulations and have a new question regarding electro- and photo-nuclear interactions. Previously I have only looked at secondaries from electro-nuclear interactions. Now I am studying the effect of photo-nuclear interactions to my detecor setup. In doing so I use 3.2GeV photons as beam particles and they interact with a tungsten target. Then I record all secondaries and compare the results to the electro-nuclear processes created by a electron as beam particle with the same energy.
Most distributions look as expected. But the secondary photon spectra look different. I will provide the plot I made in the following. It is the secondary photon energies from photo- and electro-nuclear interactions. My question is: why do the distributions differ for the two simulations? rp_gammae.pdf (16.9 KB)
Since I do not have access to the source code, I cannot check if this is correct or not and I have no intuition on the results other than this: since the electro-nuclear interaction is simulated with EPA (+corrections), and therefore the cross section dependent on the photo-nuclear cross section, should the distributions not look the same?
I would be very glad for any help or explanation!
Kind regards,
Laney Klipphahn
Are you sure, Laney, that the tail above 8 MeV is the product of photo-nuclear reactions?
I do not get it in the secondary photon spectrum from 3.2 GeV photon reactions on tungsten nuclei.
[As a side note, the source code is made accessible through a free institutional licence, to be discussed via a separate form, but I hardly see how digging into hundred thousand lines of code can effectively help a user to solve this kind of issues].
Hi Francesco! Thanks for your reply. I use the same code for photo- and electro-nuclear interactions, except that I exchange the electron with a photon and then record all secondaries via:
IF ( ICODE .EQ. 101 .AND. JTRACK .EQ. 7 ) THEN
And then I visualize all encountered photon energies. Maybe that is where I go wrong? Am I missing something, or including too many photons?
I’d conclude that there is a flaw in your post-processing, since your files - referring to a photon beam - give me this consistent outcome: secpho.pdf (9.5 KB)