Purpose
The purpose of this experiment is to familiarize the
student with the Geiger-Mueller counter. This counter is a
widely used pulse-counting instrument that uses gas
amplification, which makes it remarkably sensitive, but
whose simple construction makes it relatively inexpensive.
The experiments that are designed to accomplish this
purpose deal with the operating plateau of the Geiger
tube, half-life determinations, resolving-time corrections,
and the basic nuclear considerations involved.
Description
Basically, the Geiger counter consists of two electrodes
with a gas at reduced pressure between the electrodes.
The outer electrode is usually a cylinder, while the inner
(positive) electrode is a thin wire positioned in the center
of the cylinder. The voltage between these two electrodes
is maintained at such a value that virtually any ionizing
particle entering the Geiger tube will cause an electrical
avalanche within the tube. The Geiger tube used in this