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Making sense of radiation doses

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    #21
    Originally posted by TimberWolf View Post
    A lot of ways of expressing doses are being used that span different periods of time amongst other things, ...
    Here's another way.

    Down with racism. Long live miscegenation!

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      #22
      Originally posted by zeitghost
      On the geiger counter front, I notice that a number of those geiger counters have the detector covered in what looks like cling film.

      A great way to stop it counting alphas I'd have thunk.
      As far as I understand it, Geiger counters tend to be a bit tulip at detecting alpha particles anyway, except special ones, and many appear to be tulip at detecting gamma radiation too. Fortunately it seems beta radiation (electrons and positrons) is present in all the dangerous stuff that might be in the air and food after a nuclear reactor has been sick, although it needs a certain amount of training to interpret the results correctly and better instruments exist:

      Problems fission products after nuclear reactor meltdowns: Iodine-131 initially, then Caesium-137 and Strontium-90

      Iodine-131 (half life 8 days) comprising 3% of nuclear fission products. Beta decay (mostly 190 keV to 606 keV, tissue penetration of 0.6 to 2 mm) and gamma rays. 10% of radiation dose is gamma radiation (mostly 364 keV).

      Caesium-137 (half-life about 30 years). Beta emission and gamma rays from Barium-137m (662 keV). Principal source of radiation in the zone of alienation around the Chernobyl nuclear power plant. The biological half-life of caesium is rather short at about 70 days

      Strontium-90. (half life about 29 years). Beta decay, 0.546 MeV. Almost no gamma radiation. Bone seeker.

      A particularly dirty blast could presumably spread uranium-235 & 238 about too, which as far as I understand aren't that dangerous! (needs more research). Plus plutonium which is very bad and will be picked up by alpha, beta, gamma or neutron detectors.

      In fact I'm not sure what use an alpha detector would be except to detect uranium and plutonium fission, and smoke detectors and stuff?

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        #23
        Originally posted by NotAllThere View Post
        Here's another way.
        Neat.

        Also check out Median lethal dose - Wikipedia, the free encyclopedia

        For internal consumption. The poison dart frog does respectably here, as does Botox, polonium-210 and the rather group covered by ionising radiation (where alphas would do well I expect). It might have been nice to see plutonium and other radioactive substances listed individually, as per polonium, however.

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          #24
          Originally posted by zeitghost
          I've got a funny little geiger muller tube which is mostly steel.

          It counts cosmic rays at about 10 or 12 per minute.

          I didn't think it worked properly.

          When ZeitMater had radioiodine treatment, it detected her through a brick wall.

          Thousands of counts per minute.

          Maybe from gamma radiation?

          Being subjected to lots of neutrons wouldn't be much fun either, as you'd not only be radioactive, but could be classed a radiological waste too, once you're dead shortly afterwards of course.

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            #25
            Originally posted by zeitghost
            Oh yes. Definitely the gamma emissions.

            Nothing else penetrates brick walls quite like that.
            you know in blood, right, theres iron. to help move the oxygen around i think.
            what about a creature that uses lead instead ? like a radiation-proof heavy-weight tarkus-bomber







            (\__/)
            (>'.'<)
            ("")("") Born to Drink. Forced to Work

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              #26
              According to Plutonium - Wikipedia, the free encyclopedia plutonium has a metallic taste.

              It appears to be less toxic than Polonium, because polonium is more likely to have decayed before being passed out of the body.
              Down with racism. Long live miscegenation!

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                #27
                Originally posted by zeitghost
                Oh yes. Definitely the gamma emissions.

                Nothing else penetrates brick walls quite like that.
                And at high enough energy the body is invisible to them too. These would presumably originate from cosmic sources rather than nuclear reactors.
                The most biological damaging forms of gamma radiation occur in the gamma ray window, between 3 and 10 MeV, with higher energy gamma rays being less harmful because the body is relatively transparent to them.

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                  #28
                  Interesting, it's a rather attractive metal, I dare say you could make some nice jewellry from it, especially since it "glows" slightly, and you can even see it when your eyes are closed.
                  I'm alright Jack

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                    #29
                    Originally posted by EternalOptimist View Post
                    you know in blood, right, theres iron. to help move the oxygen around i think.
                    what about a creature that uses lead instead ? like a radiation-proof heavy-weight tarkus-bomber







                    I came across tardigrades (hardy blighters) that can withstand something like 1,000 times a human lethal dose, and radioactivity seeking fungi that are thriving at Chernobyl (which is now a nature sanctuary). The latter use melanin, so presumably have developed a bit of a suntan.

                    Radiotrophic fungi are fungi which appear to use the pigment melanin to convert gamma radiation into chemical energy for growth.
                    Radiotrophic fungus - Wikipedia, the free encyclopedia

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                      #30
                      Originally posted by TimberWolf View Post
                      I came across tardigrades (hardy blighters) that can withstand something like 1,000 times a human lethal dose, and radioactivity seeking fungi that are thriving at Chernobyl (which is now a nature sanctuary). The latter use melanin, so presumably have developed a bit of a suntan.
                      tardigrades

                      they even sound excellent
                      (\__/)
                      (>'.'<)
                      ("")("") Born to Drink. Forced to Work

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