1. The problem statement, all variables and given/known data In my honours lab we had to perform the Gamma ray experiment in which we have to measure the operating voltage of a Geiger Muller tube for a radio active source say Cs-137. With this we want to measure the linear absorption coefficients of lead and aluminium. Test the 1/r2 dependance. We wanted to also perform computer analysis in which we did counts over certain intervals for a number of counts and of course measure the dead time of our Geiger tube. When writing the report we have to discuss the history of this experiment and the theory it is based on. Unfortunately i'm not to sure on the theory behind it, when we're given the equipment and are told to figure it out ;( I'm guessing this experiment is partially based on the Compton effect, because gamma rays that do not scatter in the right direction obviously will not reach the geiger tube. Some insight would be great.