Because the fluorescence comes off in all directions, it makes a
significant contribution to the noise as one approaches the
resolution limit of the crystals, limiting the maximum resolution
attainable. So it would be a good idea to try to reduce it, e.g.
by choosing a suitable wavelength. Air scattering increases the
noise at lower resolution, which is less serious.
George
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-3021 or -3068
Fax. +49-551-39-22582
On Wed, 22 Apr 2009, Gerard Bricogne wrote:
> Dear Jacob,
>
> I think it is because the fluorescence is incoherent, and hence
> contributes to the background rather than to the diffraction.
>
> Congratulations, by the way, for managing to spell "fluorescence"
> correctly twice within a short space! Usually it occurs as "flourescence",
> which if pronounced "flour essence" conjures up the image of a rather
> unappealing substance.
>
>
> With best wishes,
>
> Gerard.
>
> --
> On Wed, Apr 22, 2009 at 11:23:19AM -0500, Jacob Keller wrote:
> > Hello All,
> >
> > What is the reason that x-ray fluorescence is neglected in our
> experiments? Obviously it is measureable, as in EXAFS experiments to
> determine anomalous edges, but should it not play a role in the intensities
> as well? What am I missing?
> >
> > Jacob
> >
> > *******************************************
> > Jacob Pearson Keller
> > Northwestern University
> > Medical Scientist Training Program
> > Dallos Laboratory
> > F. Searle 1-240
> > 2240 Campus Drive
> > Evanston IL 60208
> > lab: 847.491.2438
> > cel: 773.608.9185
> > email: [log in to unmask]
> > *******************************************
> >
>
> --
>
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> * Gerard Bricogne [log in to unmask] *
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