How is radioactivity detected and measured?

Radioactivity is detected and measured using devices like Geiger-Muller counters, scintillation detectors, and dosimeters.

Geiger-Muller counters, often simply referred to as Geiger counters, are the most commonly used devices for detecting and measuring radioactivity. They consist of a tube filled with a low-pressure gas and a central electrode. When radiation enters the tube, it ionises the gas, creating a pulse of current that can be counted. The number of pulses per second gives a measure of the radiation intensity.

Scintillation detectors are another type of device used to detect and measure radioactivity. These detectors use certain materials that emit light, or 'scintillate', when they are struck by radiation. The light is then detected and measured by a photomultiplier tube, which converts the light into an electrical signal. The intensity of the signal gives a measure of the radiation intensity.

Dosimeters are devices used to measure the accumulated exposure to radiation over a period of time. They are often used by people who work in environments where they may be exposed to radiation, such as nuclear power plants or hospitals. Dosimeters can be worn on the body and provide a measure of the total amount of radiation to which the wearer has been exposed.

In addition to these devices, there are also other methods for detecting and measuring radioactivity. For example, cloud chambers and bubble chambers can be used to visualise the paths of radioactive particles. These devices contain a supersaturated vapour or liquid that forms visible tracks of tiny bubbles when it is ionised by radiation. The tracks can then be analysed to determine the type and energy of the radiation.

In summary, there are various methods and devices for detecting and measuring radioactivity, each with its own advantages and limitations. The choice of method depends on the specific requirements of the situation.