Borrmann effect explained

The Borrmann effect (or Borrmann–Campbell effect after Gerhard Borrmann and Herbert N. Campbell) is the anomalous increase in the intensity of X-rays transmitted through a crystal when it is being set up for Bragg reflection.

The Borrmann effect—a dramatic increase in transparency to X-ray beams—is observed when X-rays satisfying Bragg's law diffract through a perfect crystal. The minimization of absorption seen in the Borrmann effect has been explained by noting that the electric field of the X-ray beam approaches zero amplitude at the crystal planes, thus avoiding the atoms.

References

• Nasonov . Nikolai N. . Borrmann effect in parametric X-ray radiation . Physics Letters A . 260 . 5 . 20 September 1999 . 391–394 . 10.1016/S0375-9601(99)00545-9 . Elsevier . 1999PhLA..260..391N .
• Pettifer . Robert F. . Stephen P. . Collins . David . Laundy . 2009 . Quadrupole transitions revealed by Borrmann spectroscopy . . 454 . 7201 . 196–199 . 10.1038/nature07099 . 2008Natur.454..196P . 18615080. 4346649 .
• Borrmann, Gerhard; Über Extinktionsdiagramme von Quarz, Physikalische Zeitschrift 42, 157–162 (1941); Die Absorption von Röntgenstrahlen im Fall der Interferenz, Zeitschrift für Physik 127, 297–323 (1950) - original articles on Borrmann effect
• Campbell, Herbert N.; X-Ray Absorption in a Crystal Set at the Bragg Angle, Journal of Applied Physics 22, 1139 (1951)
• von Laue, Max; Die Absorption der Röntgenstrahlen in Kristallen im Interferenzfall, Acta Crystallographica 2, 106–113 (1949) - original explanation of Borrmann effect