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Bending the Rules (Gamma ray lenses)

  1. Mar 16, 2015 #1
    http://news.sciencemag.org/sites/default/files/styles/thumb_article_l/public/article_images/sn-gammarays.jpg?itok=vYTMw8My [Broken]

    Researchers at Institut Laue–Langevin have found a way to bend gamma rays.

    Gamma ray lenses, which theory had suggested were impossible, could be made from heavy elements such as gold.

    The bending in the group's experiment isn't much—about a millionth of a degree, which corresponds to a refractive index of about 1.000000001. However, it could be boosted using lenses made of materials with larger nuclei such as gold, which should contain more virtual electron-positron pairs. With some refinement, gamma-ray lenses could be made to focus beams of a specific energy.
    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Mar 16, 2015 #2
    What theory suggests that is impossible to have refraction of x-rays?
  4. Mar 17, 2015 #3


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    Staff: Mentor

    High-energy x-rays and gamma rays are effectively impossible to focus using a lens. Currently they rely on reflection of these rays off of long, concentric metal or ceramic grazing incident mirrors, or on coded apertures, which are flat grills that way less than mirrors, but require lots of post-processing to get an image.

  5. Mar 17, 2015 #4
    I know this. My problem is with a theoretical impossibility. Or breaking the rules, as the OP suggest.
  6. Mar 17, 2015 #5


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    2017 Award

    Staff: Mentor

    There is no theoretical impossibility. If you extend the usual influence to gamma rays, the deflection angles are too small to be practical. The proposed pair creation mechanism seems to enhance the deflection a lot.
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