I'm not after absolute data, just the edge-jump ratio. This would have to be
extracted by peak+arctan fitting because any spectra will have peaks and a very
limited
range between edges. If the Chantler numbers are incorrect, then perhaps the
edge-jump ratio is really 2.
Do you have a reference which can be cited?
I'll try the CXRO tool next, since CXRO specializes in soft X-rays.
mam
On 9/23/2015 11:49 PM, Jana Padeznik Gomilsek wrote:
It is very hard to measure or to calculate absolute absorption data, especially
in the
vicinity of the absorption edges and especially in the soft x-ray region.
Therefore there
are significant differences between the tables and I think nobody knows which
are better.
Chantler, for example, says the expected uncertainties of the tables in your
region are
50 % to 100 %
(http://physics.nist.gov/PhysRefData/FFast/Text2000/sec06.html#tab2).
I would doubt the Chantler's L3+.1 number, all other numbers look ok - this is
what you
can get.
jana padeznik gomilsek
Message: 3
Date: Wed, 23 Sep 2015 18:02:08 -0700
From: Matthew Marcus<mamar...@lbl.gov>
To: XAFS Analysis using Ifeffit<ifeffit@millenia.cars.aps.anl.gov>
Subject: [Ifeffit] Problem with Hephaestus at Ca L-edges
Message-ID:<56034b90.70...@lbl.gov>
Content-Type: text/plain; charset=utf-8; format=flowed
I wanted to work out the edge-jump ratio between the L3 and L2 edges of Ca
using Hephaestus. I ran into two problems:
1. The ratio implied by what it says for the unit-edge-step thickness does
not agree with that derived by computing the absorption (cm^2/gm) above and
below each edge and
dividing the difference (L3+ - L3-)/(L2+ - L2-).
2. The results differ wildly depending on which resource I use:
L3-.1 L3+.1 L2-.1 L2+.1 (L1+ -
L1-)/(L2+ - L2-)
Elam 4759.796 27837.796 27478.018 38434.277 2.106375908
Chantler 4322.6 6547.121 32827.61 35436.543 0.852655473
Cromer-Leiberman 4288.524 33471.375 32786.294 47072.991 2.042659055
The Henke table doesn't yield an L2 edge jump at all, while the Shaltout yields
the same results as Cromer-Leiberman. Which one should I trust and why?
This is old-style H. (V0.18), not Demeter.
mam
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