Hello,
I am quite new FLUKA and currently trying to simulate the cosmic ray iteraction with the solar environment inorder to study the gamma ray emission coming from sun. I have scrolled through the FLUKA courses from 2019 and 2021. I have some basic questions to discuss and gradually build upon that.
The current geometry I am using is very simple - Concentric spheres with appropriate materials denoting different layers of the solar environment.
I want to simulate an isotropic GCR source, a spherical source surface concentric to the sun atmosphere. I have been going into rabit holes regarding the ways to do it. I have familiarised myself witht the new_source routine. The thing I am confused about is where the default GCR-SPE cards along with SPECSOUR card can be used to simulate what I am trying to do or are they only specific to studies with the Earth’s atmosphere?
As a preliminary step, to observe the gamma ray fluence crossing a particular boundary defined by USERBDX after the CR interaction, what other cards (Physics cards, threshold cards etc) needs to be activated?
From my understanding of the description of your problem, you can use the SPECSOUR and GCR-SPE cards to achieve your goal. You can set up the SPECSOUR card by setting the particle injection radius in WHAT(2). You can have a look at section 16.7 of the FLUKA manual for more details.
Given that you are not using the standard FLUKA geometry of the Earth atmosphere, I strongly recommend to use the option NO-NORM in the GCR-SPE card. This option will get rid of the built-in normalization of the Earth atmosphere’s layers and you can always apply the proper normalization in post-process. Please note that for running the simulation with the NO-NORM option, a folder called gcr must be present in the folder where you run your simulation: the grc folder must contains all the *.spc, renamed as follows:
01NO-NORM.spc
02NO-NORM.spc
03NO-NORM.spc
...
Other physics/transport cards will mainly depend on your physics problem.
Finally, for GCR applications make sure you link your executable to DPMJET.
Thanks a lot for getting back to the queries. At the moment, this solution worked out for me. I would post further question in this topic as I proceed with further simulation.