Based on roughly 1500 complete Laue data sets
containing more than 45000 Laue patterns,
I can say the following:
How to collect Laue data?
1.) put crystal on (capillary or cryo is fine)
2.) switch on X-rays (or Neutrons)
for time-resolved studies select one or more pulses
else forget pulses
2a) for time-resolved studies scan the crystal edge at reduced
Xray-flux to skim only surface that is hit by the Laser
after edge scan expose to full X-ray pulses
else forget about edge scan
3.) switch off X-rays (or Neutrons)
4.) read out pattern
5.) set crystal to another orientation
delta phi is dependent on the bandwidth
(approx. formula available in Ren et al., 1999)
is usually 2-3 deg with 10% bandwidth
eg 0.1 A bandwidth at 1 A mean wavelength
provided by undulators
6.) goto step 2.) and repeat until reciprocal
space covered
7.) reduce data with program. in my perception,
the BEST and MOST USER FRIENDLY for X-ray Laue is:
Precognition/Epinorm (RenzResearch)
> 20 data sets per day can be achieved!!!
(I achieved once 56 data sets in 2 days).
Get a faster computer or more processors
increases speed.
8.) based on an idea by Anfinrud/Schotte step 5
can be made much more complicated with randomly filling
gaps. Very nice feature, since it fills reciprocal
space randomly, and if crystal dies you have at
least random (but not complete) coverage of reciprocal
space.
You may also translate the crystal a bit to expose
a fresh pristine crystal volume.
9.) If it works (mosaicity can still work against you),
enjoy data that are as good as monochromatic, and
they will give perfect maps.
10.) refine model with CNS or refmac or any other
refinement program.
Best
Marius
> To all Laue experts up here
> How does a Laue data is collected?
>
> Thanks in advance to all
> PSP
>
> On Fri, Jan 28, 2011 at 3:43 AM, REX PALMER
> <rex.pal...@btinternet.com>wrote:
>
>> What programs are available for processing Laue data to produce an
>> intensity data set?
>> Are explanatory notes or publications available?
>>
>> Rex Palmer
>> Birkbeck College
>>
>
>
> --
> Pius S Padayatti
Dr.habil. Marius Schmidt
Asst. Professor
University of Wisconsin-Milwaukee
Department of Physics Room 454
1900 E. Kenwood Blvd.
Milwaukee, WI 53211
phone: +1-414-229-4338
email: m-schm...@uwm.edu
http://users.physik.tu-muenchen.de/marius/
