I am building a cosmic ray detector and I am following these designs: http://www.lbl.gov/abc/cosmic/documentation/CosmicDetector2-0.pdf [Broken] I have a few questions for those who may be familiar with this. a) In the parts page (http://www.lbl.gov/abc/cosmic/parts.html) I see that the price for the "integrated base and photomultiplier tube" is very expensive, so I opted for the separate base and PMT. My question is will I be able to use a different PMT tube for this detector than the one that is linked in the parts page? Also where exactly could I find the "base" that it is talking about. I would essentially just like to know exactly what the PMT that I choose would have to have in order to be compatible with this design. (ex. # of pins, brand, etc.) b) Is it possible for me to find or make some of the other materials for a much cheaper price and still be compatible with the design? I am primarily talking about the 2 scintillator parts (plastic and paddle) and the optical cement. I really like the design for this, but the prices for their linked parts are exorbitant. I feel like I am fine with the construction of the circuit board and its design, but I would just like to know more about the rest of the design (scintillator paddles and PMT) and if there is maybe a simpler circuit board and design that I could use. Any other information you have or can find on this topic is also extremely appreciated. I hope I put this in the right place, but it seems like an engineering problem to me. Thanks in advance for all of the help!