Many, many, many years ago in a galaxy far away I wrote a paper that probably no-one read that had some systematic data on this for a double mirror parallel beam system (second mirror as an ‘analyzer’) in flat-plate theta-theta geometry. This setup is much more sensitive to displacement than most but readily shows the effect on position and intensity. Hunt around in J.Appl.Cryst. for 2003 and you should be able to find it buried under a pile of more interesting papers… ;-)
Pam Dr Pamela Whitfield MRSC CChem Instrument Scientist – POWGEN Spallation Neutron Source Oak Ridge National Laboratory PO Box 2008, MS-6475 Oak Ridge, TN 37831-6475 Tel: (865) 235-2605<tel:%28865%29%20235-2605> Fax: (865) 574-6080<tel:%28865%29%20574-6080> Chair: IUCr Commission on Powder Diffraction From: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] On Behalf Of Nicolich, Jeffrey Sent: Thursday, February 02, 2017 1:36 PM To: Shay Tirosh Cc: rietveld_l@ill.fr Subject: RE: 2-teta shift due to sample displacement in parallel beam Shay, The important part is to have a parallel beam analyzer (crystal, parallel plate collimator or equivalent). The analyzer will then define the 2-theta position, not the sample. A more interesting question is regarding the intensities. Sample displacement will affect intensities in parallel beam geometry. The relationship depends on many factors, e.g. fixed or symmetric incident angle, surface roughness, sample transparency, flat plate or capillary, … Jeff Jeffrey Nicolich, Ph.D. | Principal Scientist GCP Applied Technologies 62 Whittemore Avenue | Cambridge, MA 02140 | T +1 617.498.3816 | jeffrey.nicol...@gcpat.com<mailto:jeffrey.nicol...@gcpat.com> THIS E-MAIL AND ANY ATTACHED FILES ARE CONFIDENTIAL AND MAY BE LEGALLY PRIVILEGED. If you are not the addressee, any disclosure, reproduction, copying, distribution, or use of this communication is strictly prohibited. If you have received this transmission in error please notify the sender immediately and then delete this e-mail. From: rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr> [mailto:rietveld_l-requ...@ill.fr] On Behalf Of Martin Vickers Sent: Thursday, February 02, 2017 1:21 PM To: Shay Tirosh Cc: rietveld_l@ill.fr<mailto:rietveld_l@ill.fr> Subject: Re: 2-teta shift due to sample displacement in parallel beam Hi, Shay. The sample displacement / peak-position relationship is equivalent. Martin On 2 February 2017 at 15:14, Shay Tirosh <stiro...@gmail.com<mailto:stiro...@gmail.com>> wrote: Dear Rietvelders Does the 2-teta shift due to sample displacement in parallel beam is similar to Bragg Brentano mode? If not then what is the mathematical expression in parallel beam? Thanks Shay -- _________________________________________________ Dr. Shay Tirosh Institute for Nanotechnology & Advanced Materials Bar Ilan University Ramat Gan, 52900 Israel Phone: +972-(0)30-531-7320 Mobile: +972-(0)54-8834533<tel:+972%2054-883-4533> Email: stiro...@gmail.com<mailto:stiro...@gmail.com> _________________________________________________ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com<mailto:alan.he...@neutronoptics.com>> Send commands to <lists...@ill.fr<mailto:lists...@ill.fr>> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -- Martin Vickers Dept. of Chemistry, UCL, 20, Gordon Street WC1H 0AJ 020 7679 5592 (or ex 25592)
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
