>>10901623the shot noise experiment is cheap, just need some dry ice and a decent oscilloscope. photoelectric effect is cheap too, main expense is a monochromator and a very dark room.
Franck Hertz has some premise setups you can buy for a couple of grand.
for particle physics you can make a cloud chamber pretty cheaply:
https://youtu.be/xky3f1aSkB8a PMT or a good photodiode is cheap, so if you have a dark room and some optical filters you could see individual photon hits in your PMT. not very exciting though
