Dear all,
I am shocked by my own ignorance, and you feel free to do the same, but
do you agree with me that according to Bragg's Law
a diffraction maximum at an angle theta has contributions
to its intensity from planes at a spacing d for order 1,
planes of spacing 2*d for order n=2, etc. etc.?
In other words as the diffraction angle is a function of n/d:
theta=arcsin(lambda/2 * n/d)
several indices are associated with diffraction at the same angle?
(I guess one could also prove the same result by
a number of Ewald constructions using Ewald spheres
of radius (1/n*lambda with n=1,2,3 ...)
All textbooks I know on the argument neglect to mention this
and in fact only n=1 is ever considered.
Does anybody know a book where this trivial issue is discussed?
Thanks!
Ciao
Pietro
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Dr. Pietro Roversi
Oxford University Biochemistry Department - Glycobiology Division
South Parks Road
Oxford OX1 3QU England - UK
Tel. 0044 1865 275339
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