Strontium in Leitz and Kodak Fluro Lenses, Radiation Sources

Strontium in Leitz and Kodak Fluro Lenses, Radiation Sources

  1. Mustafa Umut Sarac

    Mustafa Umut Sarac Member

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    Mustafa Umut Sarac submitted a new resource:

    Strontium in Leitz and Kodak Fluro Lenses, Radiation Sources - Strontium in Leitz and Kodak Fluro Lenses, Radiation Sources

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  2. Maris

    Maris Member

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    Natural Strontium is not radioactive.
    The synthetic element Strontium 90 is produced in a number of nuclear processes but does not occur naturally. Strontium 90 has a half life of about 29 years and undergoes low energy beta decay. The radioactivity is so mild that your skin would protect you if you held a lump of it.
    What makes 90Sr probably the most dangerous component of nuclear fallout is that the human body can't distinguish it from Calcium. It gets built into the bones where its radioactivity smashes biological processes at point blank range.
    Tragically, children forming and laying down bone are most at risk. Treatment is difficult because whatever pulls 90Sr out of the body depletes Calcium as well.
     
  3. Mustafa Umut Sarac

    Mustafa Umut Sarac Member

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    Maris,

    Thank you shedding more light. Do glass makers use natural or manmade strontium ?

    Thank you,
    Umut
     
  4. Mustafa Umut Sarac

    Mustafa Umut Sarac Member

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    Our friend Maris sent me a pm and I find it I must put it here.

    The radioactive Strontium 90 did not exist freely on earth before the atomic and thermonuclear atmospheric bomb tests in the 1950s and 1960s. It cannot be used in the making of glass because it undergoes beta decay into Yttrium 90 and this spontaneous conversion has a half life of only 28.8 years. The Yttrium 90 changes to Zirconium 90 and this reaction has a half life of only 64 hours. Any glass made of radioactive Strontium would crumble into Zirconium sand in only a few decades.
     
  5. cmacd123

    cmacd123 Subscriber

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    Thorium was commonly used in Lens glass. Most often found in the Pentax f1.4 screw mount lenses. Turns the Glass Yellow with time, but a day or two in strong sunlight seems to bleach it back. (don't accidentally focus the light and start a fire).

    yes, Thorium IS radioactive.

    For more details try to find a copy of Living With Radiation: The First Hundred Years
    By William Kolb and Paul Frame { http://periodictable.com/Files/LivingWithRadiation.html }