Greetings, currently I'm working with cosmic rays (merely researching, not so much as working) and now I have a question regarding cosmic rays and cosmic rays detectors (specifically, Cherenkov detectors). How is the number of photons detected by the PMT's (photomultiplier tubes) related to the direction and composition of the original cosmic ray (as the PMTs detect the photons produced by the Extensive Air Shower, not the cosmic ray itself)? Is there a formula for this? Also, if you know of any other source of information regarding technical aspects of cosmic ray detection, that would be very much appreciated. Thanks for your attention!