# Physical processes taking place inside Germanium detectors

Reading about differences between Silicon detectors and Germanium detectors, I decided to learn a bit more about the latter, since I've always used Silicon detectors in all the experiments I worked for. While reading about them, I found that Germanium detectors are usually calibrated using $^{60}$Co sources. These sources emit gammas in the ~MeV energy range, but I was wondering what is the process taking place in this measurement, is it photoelectric effect, Compton scattering or pair production? I ask this question because I do not have in mind the energy range of these processes and I know that, for example for gamma-ray satellites like Fermi, that uses a silicon tracker, the dominant effect is pair-production. On the other hand, I also know that gamma-ray satellites of lower energy like Comptel use the Compton effect. There are other gamma-ray satellites proposed as eAstrogam that use both effects. So I was wondering, at MeV energies, of those that I have mention, which one (or which ones) is negligible to measure the total energy of the $^{60}$Co emission?

• Welcome to Physics! Your initial questions are very interesting and I hope you'll stick around. – rob May 3 '18 at 19:27