Radiation: Key Definitions

12345678910111213141516171819202122232425
Across
  1. 2. A radiation detector often worn by people who work with radioactive materials to monitor the radiation dose that they are exposed to. It uses different filters which blacken or ‘fog’ when radiation hits them.
  2. 6. The absorbed dose multiplied by the radiation weighting factor.
  3. 7. The energy absorbed by a material per unit mass.
  4. 9. An indicator of the relative biological effect of radiation on a material.
  5. 10. Radiation that is all around us and is caused by both natural and artificial sources, e.g. radon gas.
  6. 12. The time taken for the activity of a radioactive source to decrease to half its original value.
  7. 18. A particle with neutral charge that exists in the nucleus of an atom.
  8. 20. A positively charged particle in the nucleus of an atom.
  9. 21. The equivalent dose per unit time.
  10. 22. The addition or removal of an electron from a neutral atom.
  11. 23. When unstable nuclei emit nuclear radiation in the form of an alpha particle, beta particle or gamma ray in an attempt to become more stable.
  12. 24. The small, dense region containing protons and neutrons at the centre of an atom.
  13. 25. A negatively charged particle that orbits the nucleus of an atom.
Down
  1. 1. The process of small nuclei joining together to form a larger nucleus, with energy being released.
  2. 3. An electromagnetic wave of very high frequency and energy.
  3. 4. The use of powerful magnetic fields to prevent hydrogen plasma from physically touching any parts of a nuclear reactor.
  4. 5. The act of placing a material between a person and a radioactive source to absorb radiation.
  5. 8. A radiation detector that counts the flashes of light produced when radiation hits the scintillating material.
  6. 11. A fast moving electron.
  7. 13. An overall neutral particle consisting of a nucleus (protons and neutrons) and orbiting electrons.
  8. 14. When neutrons released in nuclear fission reactions go on to hit other nuclei, causing further fission reactions, and the cycle repeats. The process may be controlled (nuclear reactors) or uncontrolled (nuclear bomb).
  9. 15. A radiation detector that uses the ionisation of gas in the tube to count the number of times radiation hits it.
  10. 16. The process in which an unstable, heavy atomic nucleus splits into two or more lighter nuclei (called fission fragments), with energy being released.
  11. 17. A particle made up of 2 protons and 2 neutrons. It is also the nucleus of a helium atom.
  12. 19. The number of nuclear decays (or disintegrations) per second.