Measuring the Dead Time of a Geiger Counter

Because of the time distribution of random events, it is possible that two events are very close in time, so that the second event is lost by the detector, due to its dead time. This problem is first discussed here from a theoretical point of view, reporting working plots to show the amount of possible loss of events and considering the formulae for dead time corrections. Different set of measurements obtained with a Geiger counter and by the use of gamma and beta radioactive sources are then analysed, using the technique which employs two radioactive sources to estimate the dead time of the counter.