Hi all, The GSAS manual is great, and so is GSAS - but in the case of IPOLA and IPOL, I have to admit that the GSAS manual is ambiguous, so I had to do the following recently when I had to set up a new diffractometer: Do a Google search on the word IPOLA, and the first entry will be a wonderful discussion of the polarization parameters, including contributions from Bob Von Dreele, and I was able to set up my polarization correctly using that discussion. Good luck! - Kurt
________________________________ From: Brian H. Toby [mailto:[EMAIL PROTECTED] Sent: Thu 8/7/2008 10:04 AM To: [EMAIL PROTECTED] Cc: [email protected] Subject: Re: confusion about some GSAS parameters On Aug 7, 2008, at 12:02 PM, [EMAIL PROTECTED] wrote: So, for the case of a brag brenteno diffractometer without any monochromator, will the value for POLA should be fixed to zero?? There are two GSAS polarization models (read the manual!), but my recollection is that for IPOLA=0, POLA should be 0.5 when you have no monochromator or analyzer. Brian
