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Beer-Lambert relation to dosage

  1. Feb 23, 2015 #1
    So as I understand Beer-Lambert, it describes the attenuation of intensity/flux/fluence. My question is, suppose you have:
    • some set object of interest
    • fixed at some far distance from a source (so the rays are ~parallel)
    • a shield (e.g. layer of lead) is placed in front of the object, that reduces the radiation intensity by, say 50%
    Then would this necessarily result in a 50% reduction in exposure and absorbed dose?

    Thanks in advance!
  2. jcsd
  3. Feb 24, 2015 #2


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    Yes, definitely. If you have half the intensity hitting you, you necessarily have half the dose. It's energy conservation.

    ETA: Well, no. You can have, say, x-rays produced from the scattering of the gammas on atomic electrons. So you could get a dose from the x-rays.
  4. Feb 24, 2015 #3


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    Well I think the distance will also play a role, since the flux drops with distance squared. But if you keep the distance as fixed, and you want to look at the particular "dose" you will get from such a distance, then yes the absorber will do exactly that job...
  5. Feb 24, 2015 #4


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    That is an important point. The flux of the initial radiation of whatever type will reduce by 50% if Beer-Lambert is applicable, but you can get secondary particles. In the worst case (very high-energetic primary particles), the absorbed dose of material behind the shielding increases.
  6. Feb 25, 2015 #5
    This is the sort of thing that had me concerned. Also whether the exposure to absorbed dose is necessarily linear. Thank you all for your feedback.
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