Hello everyone, I would like to ask a couple of questions related with the interaction mechanisms of photons and electrons with matter. Through searching about this subject, I have concluded that they both have different penetration depth and different interaction mechanisms. But apart from this general notation, I have unfortunately failded to find something more specific. The obvious things that anyone could say, is that among other qualities, electrons do not have charge or mass like electrons do and thus they should undergo different interactions. But the question is what are those differences? For example I learned thanks to Zz in the thread about Auger Vs Secondary Electrons, that in an experiment where the incident beam uses photons, we will never get Secondary electrons. Why? Because we call secondary, the electrons that come out after primary electrons have interacted with matter. But in a very specific experiment, where we use incident electrons and we are interested in making a graph of Secondary electron yield VS Primary electron energy (ev), what would be the difference if we used incident photons instead of electrons, of the same energy? Finally, what would the result be, if we did a XRD experiment and we used electrons instead of X rays, with the same energy? Of course, I know that it is not ideal to suppose that there is a magical way to do something like that, but what I wanted to do through this example was to further clarify my question's point. Thanks a lot for your time. I hope my question is clear enough.