I am a new FLUKA user, trying to simulate the interaction of gammas in a gas (Ar) for my bachelor thesis.
The whole idea is, to look if there is a correlation between the angle of the incoming gamma and the angle of the produced electrons. I already have built the geometry but now I am not sure about the scoring.
To get the angle of the electrons I assumed, that I needed the USERDUMP routine with a specific mgdraw, so I can get the xyz-coordinates of the electron creation point and the xyz-coordinates when the electron passes out of the gas. With these coordinates I assumes, could calculate the angle.
Is this logical or is there another/better way of finding the angle of the electrons?
Using mgdraw to score the angles and positions of the incoming photon and outgoing electron is the best way.
Unfortunately, the USERYIELD card will give you the angle with respect to a fixed direction. In theory this could be used but I suspect it would prove more complex.
Let me know if you have any troubles with mgdraw - but I hope this helps
thank you for your answer. I tried the mgdraw and got it to work for counting the seperate interactions, just for testing and information reasons.
For the electron angle I got the suggestion, that i can just get the momentum from the particles at the interaction point and calculate the angle using it. I’m just thinking about, what happens if there is multiple compton scattering for a photon. I assumed, that is has the same NCASE so I can iterate over them and mean them, if there are multiple interaction with the same NCASE. If you have an opinion on this idea feel free to let me know.
Otherwise thank you again and if I’m running into any problems with the mgdraw I will write again.
You are quite correct, NCASE is shared across all the interactions of the same primary even if the interaction (ICODE) would be different.
If you wanted the angle between the incoming photon and the outgoing electron you could use TRACKR: CXTRCK, CYTRCK, CZTRCK (direction cosines photon) and GENSTK: CXR(i), CYR(i), CZR(i) for the i-th secondary(direction cosines of secondary) before MCS occurs.
