That's right. LP refinement works just fine within TOPAS but angular range as wide as possible is needed. If it is up to 140-150 deg. 2thteta LP does not correlate much with thermal parameters. Refined LP is not exact but very close.
Peter Zavalij X-ray Crystallographic Center University of Maryland College Park, MD Office: (301)405-1861 Lab: (301)405-3230 Fax: (301)314-9121 -----Original Message----- From: Kurt Leinenweber [mailto:ku...@asu.edu] Sent: Saturday, July 25, 2009 8:53 PM To: alor...@unex.es; Leonid Solovyov Cc: rietveld_l@ill.fr Subject: RE: LP factor in the Rietveld refinement Hi all, I haven't actually DONE this, so maybe I shouldn't put my 2 cents in, but can't you refine the polarization factor by using a standard such as Y2O3 and fixing the structure and thermal parameters of the standard while refining the polarization angle? The angle so obtained should agree with what the theory tells you for your diffractometer configuration, but it seems more comforting to verify it by a measurement. - Kurt ________________________________ From: alor...@unex.es [mailto:alor...@unex.es] Sent: Sat 7/25/2009 1:29 PM To: Leonid Solovyov Cc: rietveld_l@ill.fr Subject: Re: LP factor in the Rietveld refinement In this context: What about the LP for a Goebel mirror followed by a 4-bounce or 2-bounce primary monochromator? Best regards angel l. ortiz > > As far as I know, for X-ray mirrors the LP angle is near zero. > > Leonid > > ******************************************************* > Leonid A. Solovyov > Institute of Chemistry and Chemical Technology > 660049, K. Marx 42, Krasnoyarsk , Russia > www.icct.ru/eng/content/persons/Sol_LA > www.geocities.com/l_solovyov > ******************************************************* > > --- On Sat, 7/25/09, chu...@hkusua.hku.hk <chu...@hkusua.hku.hk> wrote: > >> From: chu...@hkusua.hku.hk <chu...@hkusua.hku.hk> >> Subject: Re: LP factor in the Rietveld refinement >> To: "Ross H Colman" <ucca...@ucl.ac.uk> >> Cc: rietveld_l@ill.fr >> Date: Saturday, July 25, 2009, 4:16 AM >> Dear Ross, >> >> How about the LP factor/monochromator angle if using Gobel >> mirror in >> my D8 system? >> >> Thanks! >> >> stephen >> > > > > > No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.392 / Virus Database: 270.13.30/2262 - Release Date: 07/25/09 18:01:00
