Uses of Radiation Flashcards
How can you use radiation to diagnose cancer?
- A tracer solution containing a source of gamma rays is injected in the body.
- The tracer collects where there’s abnormal activity.
- The gamma rays are detected using a ‘gamma camera’
How can you use radiation to treat cancer?
Gamma rays as beams of radiation can target and kill cancer cells because gamma rays are very penetrative.
How can you use radiation to sterilise and irradiate?
Food and equipment can be sterilised and irradiated. Plastic medical equipments is irradiated with gamma rays to kill germs unlike metal appliances that are usually heated because if you heated the plastic it would melt.
Gamma rays can also be used to have the same effect on food.
What source of radiation to smoke alarms contain?
Alpha
What radioisotope do smoke alarms usually contain?
Americium-241
How do smoke alarms work?
- The alpha source releases particles to ionise the air to give electrons and ions
- The charges particles attract to the oppositely charged plate and allow a small current to flow.
- The air is constantly being ionised, so as long as the current is flowing the alarm won’t sound.
What happens when smoke enters the smoke alarm?
The smoke absorbs the alpha particles which stops the air ionising and the current from flowing.
When does the alarm sound?
When the current drops below a certain level.
What radiation source checks the thickness of paper?
Beta
What happens when the paper is too thin?
More beta particles penetrate and the detector records higher count rate, a computer then registers this and reduces the pressure applied to the rollers to make thicker paper.
How can tracers be used in the environment?
Radioactive isotopes can be added to water as tracers to monitor things like pollution.
