Radiation

• Proton number (atomic number)

  The number of protons in an atom/nucleas
• Nucleon number (mass number)

  Number of protons and neutrons in the atom/nucleas
• Isotopes


  Atoms of the same element which have the same number of protons but a different number of neutrons
• Radioactive emissions as arising from unstable atomic nuclei because of an imbalance between the number of protons and neutrons
• Radioactive decay


  The nucleas tries to become stable by breaking up into stable fragments
• Background radiation

  Radiation around us all the time
• Correcting for background radiation

  • Let the GM tube (radiation detector) detects radiation when there are not radiation sources present.
  • This should be done for a long period of time/repeated.
  • Subtract the value from all readings taken with the source.
• At low levels of radiation exposer, the bodies natural repair mechanisms repair radiation damage to cells
• Protection from radiation sources

  • Limiting time - reduces dose
  • Distance - intensity decreases
  • Sheilding - Barriers of lead, concrete, water etc.
  • Containment - Closed systems, barriers
• Dangers of radiation - outside the body

  Alpha - cannot harm as it is stopped by skin and air

  Beta - is ionising and can damage soft tissue

  Gamma - dangerous as it can penetrate the body, it can also mutate cells and cause cancer
• Dangers of radiation - inside body/injested

  Alpha - dangerous as it is most ionising and easily absorbed

  Beta - ionising but less easily absorbed

  Gamma - least dangerous as it is least ionising and least absorbent
• Alpha

  Identical to the nucleas of a helium atom
• Beta

  Fast moving/high energy electron
• Gamma

  High energy electromagnetic wave
• Alpha is stopped by air, skin and paper
• Beta is stopped by aluminium
• Gamma is stopped by several cm of lead/very thick concrete
• Nuclear Waste Disposal

  • Cooled and turned to glass
  • Stored in steel drums
  • Sealed in concrete
  • Put deep underground
• Radiation Experiment

  1. Find background radiation
  2. Find total count (without absorbers)
  3. Put paper infront of source and take a reading, if reduced alpha is present
  4. Put aluminium in front of source and take a reading, if reduced beta is present
  5. Any radiation left is gamma
  6. Lead shows it will reduce gamma
  7. Subtract background radiation from all readings
• Radiation readings must be taken over a long period of time and repeated because radiation is random
• Alpha Decay

  Number of protons decreases by 2, nucleon number decreases by 4
• Beta Decay


  Number of protons decrease by 1, nucleon number stays the same
• Background radiation is made up of cosmic rays, radon gas, hospital radiation, food and drink, buildings, nuclear waste
• Symbol for Gamma

  
• Symbol for Alpha

  
• Symbol for Beta