Ionising Radiation & Detectors
- Ionising radiation include alpha, beta and high-energy electromagnetic radiation such as X-rays, gamma rays and UV
- They are used in smoke detectors and in many medical applications, such as:
- Disinfecting medical instruments
- X-rays
- Radiotherapy
- CT scans
- These normally use X-rays, gamma rays or radioactive tracers
- In those areas of industry and medicine, where people are routinely working with ionising radiations, various safety procedures are put in place
- Workers are routinely monitored to check the levels of radiation that they are exposed to and strict limits are placed on what they can receive
A badge containing photographic film can be used to monitor a person’s exposure to radiation
- Limits are often placed on the amount of time that workers can spend using radioactive materials.
- Where feasible, barriers will be placed between the worker and the source in order to absorb the radiation
- Doctors, for example, will leave the room whilst carrying out certain procedures (including x-rays) in order to minimise exposure.
- Areas or containers that pose a radiation hazard should have the appropriate radiation hazard symbol
Radiation hazard symbol
- The universal radiation symbol is important, so people that speak any language can still understand its meaning
Radiation Detectors
- Radiation can be detected by a Geiger-Müller tube, or a geiger counter
- Geiger-Müller tubes are simple devices that detect the presence of the ions created by radiation entering the tube
- Connecting the tube to a counter allows the amount of radiation to be determined
A Geiger-Muller tube (or Geiger counter) is a common type of radiation detector
- The amount of radiation given off by an isotope each second is known as its activity and is measured in becquerels (Bq)
- An activity of one becquerel means that there is one decay per second
