Build very simple design and cost effective Geiger-Muller counter
http://manuscript.advancejournals.org/uploads/516191730f661cb3f19fce812b9f43502a855b779d2cb821f392d87702cd4c16/Manuscript/11885.pdf

This paper describes our first undergraduate project experience, final report and findings on the subject matter. Initially according to our project title, we were focused on developing a low cost detector which can detect radiation only. To make one of these kinds of detector doesn’t take much and can be prepared at fairly low cost being very common project in nuclear science arena. The Geiger-Muller tube, or GM tube, is an extremely useful and inexpensive way to detect radiation. While the GM tube can only detect the presence and intensity of radiation, this is often all that is needed.