Download A Geiger counter, sometimes called Geiger-Mueller or G

A Geiger counter, sometimes called Geiger-Mueller or G-M
Counter:
The counter is based on an air-tight tube filled with argon and
with a large voltage (500 – 1500 volts) between a cathode (the
wall of the tube) and an anode (a wire down the center).
When a high-energy particle goes into the argon, it ionizes
some of it and there is a breakdown between the cathode and
anode that we pick up as a voltage spike and count – or
amplify and hear as a “tick.”
How our experiment works:
You are going to measure the half-life of protactinium 234.
This is a beta-emitting decay product in the decay of
uranium-238; part of the series is given above:
The protactinium-234 is extracted almost completely by an
organic solvent, such as amyl acetate, from an acidified
aqueous solution of uranyl nitrate (which contains
proportionally, 1g uranyl nitrate, to 3 cm3 water, to 7 cm3
concentrated hydrochloric acid). Only the high-energy beta
particles from the decay of protactinium-234 are detected by
a G-M tube.