Energy spectrum of CoulombScat

Physics Processes, Models and Cross Sections
1

Hello all,

I am shooting 250 MeV protons at a material containing O and Ga, and see several hard edges in the resulting energy spectra of 16O and 69Ga (and other ions in the material) coming off that makes me suspect something is set incorrectly.

What I mean is: when checking the track creator process for 16O in PreUserTrackingAction, there is a distinct cliff at around 100 keV in the initial energy:
16O_noCuts.pdf (16.5 KB)

The hadElastic cliff goes away when setting the proton cuts (setCutsForAGivenParticle) to 1 um, so does this mean that those ion tracks were previously not generated due to too low energy?
16O_protonCuts1um.pdf (17.0 KB)

However, I cannot figure out what setting to change in order to get the energy spectra of ions from CoulombScat to extend down to a keV or so. The cliff position is at lower energy for heavier ions like 69Ga, which seems like there is some cut that needs to be adjusted:
69Ga_protonCuts1um.pdf (16.7 KB)

Does anyone have suggestions on how to do this?

Thank you!

2

Yes, those protons probably weren’t being generated because the cut value was too high. If you set the physics list verbosity to 1 it will print a table that shows the energy threshold for each material used.