| 1 | <html> |
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| 2 | <head> |
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| 3 | <META NAME="Author" CONTENT="Brian H. Toby"> |
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| 4 | <title>EXPGUI Tutorial #4</title> |
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| 5 | </head> |
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| 6 | <BODY BGCOLOR="#FFFFFF"> |
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| 7 | |
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| 8 | <A HREF=http://www.ncnr.nist.gov> |
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| 9 | <IMG SRC="http://www.ncnr.nist.gov/images/ncnrtrans.gif" |
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| 10 | alt="Link to NIST Center for Neutron Research home page" |
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| 11 | ALIGN=RIGHT></A> |
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| 12 | <A HREF=http://www.nist.gov> |
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| 13 | <IMG SRC="http://www.ncnr.nist.gov/images/webidblue_2lineright.gif" |
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| 14 | alt="Link to National Institute of Standards & Technology home page" |
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| 15 | ALIGN=LEFT></A> |
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| 16 | <CENTER> |
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| 17 | <A Href="http://www.ncnr.nist.gov/programs/crystallography/software/tclpkgs.html"> |
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| 18 | <IMG SRC="tcltklogo100.gif" |
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| 19 | alt="Link to Tcl/Tk information"> |
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| 20 | </CENTER></A> |
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| 21 | <hr> |
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| 22 | |
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| 23 | <CENTER> |
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| 24 | <H1>GSAS Nickel example using EXPGUI (part 4)</H1> |
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| 25 | </CENTER> |
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| 26 | <H1> |
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| 27 | 4. Change a profile parameter |
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| 28 | </H1> |
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| 29 | The next step in the tutorial is to change a profile parameter, |
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| 30 | in this case to widen the range of peaks that are fit. This is done |
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| 31 | by switching to the Profile pane and |
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| 32 | selecting each histogram by selecting it in the box |
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| 33 | to the left. Then change the "Peak cutoff" from 0.01 (1%) to 0.005 |
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| 34 | (0.5%). Note that this change can slow down GSAS significantly, but |
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| 35 | is useful when the the signal-to-noise ratio is very good. |
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| 36 | <img src="profile1.gif"> |
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| 37 | <BR clear=left> |
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| 38 | After the first histogram is modified, select the second histogram |
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| 39 | and modify the "Peak cutoff" there as well. |
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| 40 | <img src="profile2.gif"> |
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| 41 | <BR> |
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| 42 | |
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| 43 | <BR clear=left> |
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| 44 | Previous step: <A HREF="nickel3.html"> |
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| 45 | Add data (histograms) to the Experiment |
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| 46 | </A> |
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| 47 | <BR> |
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| 48 | Next step: <A HREF="nickel5.html"> |
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| 49 | Run POWPREF |
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| 50 | </A> |
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| 51 | |
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| 52 | <BR clear=left> |
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| 53 | <HR><p><a href="http://www.ncnr.nist.gov/staff/toby/">Brian Toby</a> (<a href="mailto:brian.toby@nist.gov">Brian.Toby@NIST.GOV</a>) |
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| 54 | <BR clear=left> |
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| 55 | $Revision: 207 $ $Date: 2009-12-04 23:02:11 +0000 (Fri, 04 Dec 2009) $ |
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| 56 | </body> |
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| 57 | </html> |
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