Risks and absorbed doses

Posted in Physics, Ionising radiation

Absorbing ionising radiation can cause damage to your body, and if you absorb enough, kill you. There exists a number of measurement systems to calculate the amount of radiation people are exposed to.

Absorbed dose

The absorbed does is measured in Grays (Gy) after the physicist Louis Harold Gray. 1 Gray is defined as 1 joule absorbed per kilogram of matter, the dose in grays is therefore given by the equation:

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Dose equivalent

Different types of radiation cause more harm or less depending on how ionising they are. The tissue exposed to the radiation will also react differently with rapidly dividing cells being affected more. The absorbed dose equivalent is measured in Sieverts (Sv) and is calculated by multiplying the dose in grays by a quality factor, which depends on the radiation used and the tissue exposed:

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You will be told the quality factor in any exam questions!

Risks

Risk is a concept which combines the probability of an event happening with the consequences of that even happening:

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