To detect radiation, whether it be in your home, near a radioactive waste site, or wherever else, you must have a radiation detector. Here we mention two types of radiation detectors.
Among the oldest devices for detecting the ionization caused by a photon or charged particle are the itonization chamber and the Geiger counter. Both are gas-filled tubes with electrodes that attract the electrons and ions to produce voltage pulses in external circuits. In an ionization chamber, the applied voltage is low and the output pulse is a measure of the amount of ionizaiton created. In a Geiger counter, the applied voltage is high enough to give the initaial ions sufficient energy of their own to cause an avalanche of further ionization. The result is a large output pulse that is the same of all incident photons or particles. So, in the presence of the particles, one would hear loud snaps.
The scintillation counter is based on the emission by certain substances (such as those used to make the screens of television pictures tubes) of flashes of light when struck by ionizing radiaiton. The light flashes are then picked up by a photomultiplier tube which amplifies the initial output of photoelectrons from a suitable cathode by the secondary emission of further electrons at each successive dynode. A scintillation coutner is more rapid in its operation than an ionization chamber or a Geiger counter.