Simulating a PMT as a Geant4 beginner

Hi all,

I’m in the process of building a simulation which requires a PMT to detect the scintillation (and cherenkov) photons I’ve got going, but I’m not actually sure how to go about this.

As I’m actually trying to simulate a 20 inch Hamamatsu PMT, I’ve created a thin hemisphere that acts as a (very) simplified model of the photocathode part. Beyond this, I’m not sure what I need to make this into a sensitive detector.

The plan is that the PMT records the photons and their energies, so at the end a histogram of the number of photons vs energies can be created; I know that many people choose to use ROOT to do this part, but for some reason I cannot get ROOT to compile on my virtual machine running Ubuntu, so I assume I can just get the number of photons and energies to output in a txt file?

Many thanks to anyone that can help me!