Leonid I don't know why we have such a large difference, but for some reason we do. I will send you privately the two diagrams. Mike
-----Original Message----- From: Leonid Solovyov [mailto:[EMAIL PROTECTED] Sent: 19 February 2008 03:56 To: rietveld_l@ill.fr Subject: RE: advice on new powder diffractometer Dear Mike, Normally, changing sollers must not influence the signal/background ratio. Wider sollers, however, make the primary beam wider and if the sample diameter is small then a parasitic scattering from the sample holder edges may appear. I am really surprised that moving from 0.04 Soller slits to 0.02 you got 25 times intensity reduction. When I change the primary soller from 0.04 to 0.02 the intensity drops ~2 times, so if you changed both the primary and the secondary sollers the intensity should decrease ~4 times, but not 25 times. Leonid Solovyov