Ariel
We use a Guinier camera which gives film strips linear in units of two
theta. Our samples are run with silicon as an internal standard. The film is
scanned in to a TIF file using a standard scanner with 600 DPI resolution. A
profile of intensity vs units of length is extracted using NIH Image
(http://rsb.info.nih.gov/nih-image) and exported as an ascii XY file. To
convert the arbitrary length scale into units of two theta I used "Winfit"
(http://www.geol.uni-erlangen.de)to peak pick the Si lines and a program
provided by Dr. Koeckerling ([EMAIL PROTECTED]) to get values
needed to convert the arbitrary length units to two theta values. The actual
conversion was done in an XCEL spreadsheet which can also render reasonable
graphics. The program "convert" (http://www.ceramics.irl.cri.nz/Convert.htm)
took the XY file format into GSAS format for Rietveld refinement. Our goal is
to use this relatively inexpensive, easily accessible camera to explore unknown
phases and design in-situ time resolved powder x-ray diffraction experiments
which we carry out with Jon Hanson at NSLS X7b using a translating image plate
camera developed by Poul Norby and co-workers.
The Rietveld list-serv has been invaluable to me over the last several
months of my graduate school career and I thank all the contributers. In
conjunction with my last post I wish to thank Lachlan Cranswick for making me
aware of multiple versions of "convert", as well as Nita Dragoe and Mark
Bowden for providing versions of this program for a Windows environment.
Patrik Dahlke has kindly provided an alternative program for conversion of XY
data to GSAS format. Stefan Krumm's "WinFit" is very nice and I wish to thank
him for its development and distribution.
Roger
Roger M. Sullivan
Department of Chemistry
North Carolina State University
[EMAIL PROTECTED]
