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Dear Pietro,
You may take a textbook into account which deals with Laue
diffraction. If you search for the keyword "Laue" and the author
"Helliwell" at the IUCR journals, you will get a large number of hits,
indicating that this is by no means a 'trivial' issue (e.g.
http://dx.doi.org/10.1107/S0909049599006366 for an overview or
http://dx.doi.org/10.1107/S0108767387098763 for the treatment of
harmonics).
As far as I understand, certain scaling programs take the lambda/2
contribution of monochromators into account.
Regards,
Tim Gruene
On 08/20/2013 04:36 PM, Pietro Roversi wrote:
> 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
>
>
>
> Sent from my Desktop
>
> Dr. Pietro Roversi Oxford University Biochemistry Department -
> Glycobiology Division South Parks Road Oxford OX1 3QU England - UK
> Tel. 0044 1865 275339
- --
- --
Dr Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
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