Lachlan (and others),
GSAS will handle "native" energy dispersive data just fine. The raw data is
in the "standard" GSAS format (10 fields of 8 characters) with intensities
measured in constant energy steps. The "BANK" record looks like the following:
BANK 1 2047 205 EDS 1.67141E-01 6.13157E-02 4.89310E-08 -3.53527E-12
STD
The four values after "EDS" are the coefficients for the equation
E = c(1)+c(2)*s+c(3)*s^2+c(4)*s^3
that converts step number (s) to energy in keV. These coefficients must be
determined for each instrument setup by calibration with a standard
material. Changing 2theta for the detector will change these values. If the
measured intensities are "precorrected" then the alternative "ESD" data
format can be used instead.
The instrument parameter file for EDS data looks like:
123456789012345678901234567890123456789012345678901234567890
NS BANK 1
INS 1
IRAD 0
INS HTYPE PXER
NS 1 ICONS 7.81476
INS 1I HEAD DUMMY INCIDENT SPECTRUM FOR EDS
DIFFRACTOMETER
INS 1I
ITYP 0 0.0000 150.0000 1
INS 1PRCF1 1 4 0.01
NS 1PRCF11 0.173000E-03 -0.161000E-01 0.401000E+00 0.000000E+00
A copy of this file is in the gsas distribution material as
\gsas\example\inst_x17.prm.
One should change the value on the "ICONS" record to what ever 2theta value
the detector was positioned at for your experiment.
Bob Von Dreele
At 11:01 AM 6/21/00 +0100, you wrote:
> > I have question regarding the synchrotron data. I'd like to
> >convert the Energy Dispersive Data from Synchrotron to GSAS
> >file. It composes of energy (keV) and intensity count.
> >What program should I use? Can anybody help me?
> >
> > Regards,
> > Walairat
>
>I would be interested in the procedure for GSAS to handle
>Energy Dispersive data in a native fashion.
>
>PowderX by Cheng Dong and Powder v 2.00 by Nita Dragoe
>can view, analyse and manipulate Energy Dispersive data
>in a native fashion.
>
>PowderX:
> http://www.ccp14.ac.uk/tutorial/powderx/
>
>Powder v 2.00
> Tutorial:
> http://www.ccp14.ac.uk/tutorial/powder/index.html
>Download:
>
>http://www.chem.t.u-tokyo.ac.jp/appchem/labs/kitazawa/dragoe/html/software.html
>
>http://www.ccp14.ac.uk/ccp/web-mirrors/ndragoe/appchem/labs/kitazawa/dragoe
>/html/software.html
>
>=====
>
>To trick other software into being able to use energy
>dispersive data - you could convert it into an angular
>dispersive equivalent - which in theory any common diffraction
>software could then use to a limited extent.
>
>DLConvert for Windows can do this on Daresbury SRS and Argonne
>format Energy Dispersive data.
> http://www.ccp14.ac.uk/projects/dl-conv/
>The latest version has some minor bugs that a new
>student programmer will be fixing next month and the
>best version to get for the moment is 1.26:
> http://www.ccp14.ac.uk/projects/dl-conv/Dlconv1-26.exe
>
>It will also do interpolation of the data into
>constant steps when going from Channels/KeV to
>2-theta format.
>
>Lachlan.
>
>--
>Lachlan M. D. Cranswick
>
>Collaborative Computational Project No 14 (CCP14)
> for Single Crystal and Powder Diffraction
>Daresbury Laboratory, Warrington, WA4 4AD U.K
>Tel: +44-1925-603703 Fax: +44-1925-603124
>E-mail: [EMAIL PROTECTED] Ext: 3703 Room C14
> http://www.ccp14.ac.uk
