Choice of wavelength

From: Theresa H. Hsu
Date: 13 February 2012 21:02
Hi all.

When collecting data, is there a specific wavelength to be chosen at synchrotron source? Does it make difference between 0.9 and 1.5 A, for example? I know it is important for SAD/MAD but how about MIR?

Thank you.

Theresa

----------
From: jens Preben Morth
If you are not looking for a specific metal, you can play it safe and collect a redundant native data set at 0.9 A and one at 1.5 A, to check for Ca,Cl,SO4 etc and other anomalous scatterers
cheers
Preben

----------
From: Ed Pozharski

Intensity gets weaker on the edges, so it makes sense to stay close to
the center of the beamline range.

Shorter wavelength may be helpful if you are trying to get higher
resolution.


--
Oh, suddenly throwing a giraffe into a volcano to make water is crazy?
                                               Julian, King of Lemurs

----------
From: Bernhard Rupp (Hofkristallrat a.D.)
For MIR, you also need to weigh your options.
If you want to use anomalous signal for SIRAS/MIRAS, you may want to be above the most prominent or at least a useful edge of your HA.
On the other hand, being above an HA edge increases you chance of serious radiation damage. Sometimes you may need to back-soak.
For light atoms, higher energy generally means less absorption.
All depends on many details which you do  not provide.

BR