[Ifeffit] Re: ? about l_scmt etc.

Peter Pfalzer peter.pfalzer at physik.uni-augsburg.de
Wed Sep 15 02:18:13 CDT 2004

Hi Kristine, Matt,

I just remembered a discussion on the (meanwhile rather inactive?!) feffusers 
list concerning ELLIPTICITY and thought I should quote that.

>>Oh... one more question... I haven't been using the ellipticity
>>card in the feff.inp file, even though I've been using
>>"POLARIZATION 1 0 0"... is this OK?
> Yes, the ellipticity card is for describing polarizations that are
> not linear, such as for magnetic circular dichroism.  For your
> surface EXAFS experiments at APS 5-ID, the x-rays were highly
> linearly polarized.

As of 2002-04-25 Alex Ankudinov wrote:
- - - - snip - - - -
ELLIPTICITY specifies the direction of incoming x-ray
and the ratio of intensities along two perpendicular
directions, one of which is specified by POLARIZATION card
and the other is found automatically.

ELLIPTICITY is not intended to be used for circular polarized light.
One has to use XMCD card, which assumes 100%  circular polarized light.
- - - - snip - - - -

Best, Peter

Peter Pfalzer
Universitaet Augsburg                    Tel: +49-821-598-3215
Lehrstuhl fuer Experimentalphysik II     Fax: +49-821-598-3411
Universitaetsstr. 1
D-86135 Augsburg
Germany                   Peter.Pfalzer at physik.uni-augsburg.de

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