2 Nov 2010 07:13:42 -0800
From: Scott Calvin
To: XAFS Analysis using Ifeffit
Subject: Re: [Ifeffit] Transmission EXAFS sample
Message-ID:<5b5040d9-f501-4ba0-8f24-38630b43b...@gmail.edu>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
To my mind, when considering sample pre
Hi Edmund,
Thanks for that post... I'd never seen the UV-vis literature on this
and didn't know what a Ringbom plot was. A google search led to
Ramirez-Munoz 1967 (doi:10.1016/0026-265X(67)90042-2) on
Atomic-Absorption Photometry, which shows a very nice result that
significant distortions don'
On Nov 22, 2010, at 7:09 AM, Jatinkumar Rana wrote:
Hi Scott,
Sorry for mixing up the things.
For the case, when i have very limited amount of sample that i can not
cover 1sq.cm area, you, Matt and others have given very very clear
explanation about possible solutions and the probable effect
To my mind, when considering sample preparation the important thing is
not so much the "right" thickness, as knowing the effects to guard
against as the thickness deviates toward the thin or thick side.
As transmission samples become thicker, the problem of "unwanted"
photons becomes more s
atinkumar Rana
To:ifeffit@millenia.cars.aps.anl.gov
Subject: Re: [Ifeffit] Transmission EXAFS sample
Message-ID:<4ce8f809.3040...@helmholtz-berlin.de>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 20.11.2010 19:00,ifeffit-requ...@millenia.cars.aps.anl.gov wrote:
Send Ifeffit mailing list
Dear Jatin,
the optimum mued of 2.x is not just derived by simple photon counting
statistics. As Matt pointed out, for transmission measurements at a
synchrotron beamline in conventional scanning mode this is seldom a
matter. Nevertheless, one should avoid to measure subtle changes of
absorpt
On Nov 21, 2010, at 2:45 AM, Jatinkumar Rana wrote:
Hi Scott,
Yes I have assumed the sample cross section area to be 1 sq. cm. and
then calculated the amount of sample required for that.
What i planned is following :
I would calculate the amount of sample required for 1sq.cm area, take
th
FS Analysis using Ifeffit
Subject: Re: [Ifeffit] Transmission EXAFS sample
Message-ID:
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Hi Jatin,
Matt covered most of what I would say, but I'll add a few comments of
my own.
I'm not sure how you arrived at the conclusi
That's probably how they discovered graphene, by trying to make exafs
sample.
Anatoly
Sent from my mobile phone, please forgive typos.
-Original message-
From: Scott Calvin
To: XAFS Analysis using Ifeffit
Sent: Fri, Nov 19, 2010 18:30:37 GMT+00:00
Subject: Re: [Ifeffit] Transmi
Hi Jatin,
Matt covered most of what I would say, but I'll add a few comments of
my own.
I'm not sure how you arrived at the conclusion that you have only a
few percent of what you need--you must be assuming a sample area
somehow. I have frequently made transmission measurements on samples
Dear Jatin,
The idea that the optimum absorption length (mu*t) for transmission
experiments is 2.3 assumes that the errors in the measurement are due
to counting statistics of the x-rays. For any synchrotron experiment,
the number of x-rays in the transmission chamber is high enough that
the nois
Hi Jatin
from my modest experience the problem comes with the noise from
detectors (typically from ionisation chambers- before and after sample).
When the sample is too thick than signal/noise ratio becomes smaller,
that means you are limited in k space. I have measured liquid samples
with edg
Dear all,
I have very basic question about the sample preparation for EXAFS. It is
well understood and proven by several researchers that the optimum
amount of sample (per unit area) required for EXAFS is determined by the
fact that the total absorbtion of the entire sample above the absorptio
13 matches
Mail list logo
