2009 APS XAFS School

Dates: July 6—10

The APS XAFS School is open to anyone interested in learning about XAFS and how to incorporate XAFS into their own research program. The curriculum is aimed at the novice to intermediate level XAFS practitioner and covers all aspects of XAFS. Lectures cover topics ranging from sample preparation to theory to data analysis. Two afternoons are devoted to hands-on experiments at APS spectroscopy beamlines 5 BM-D, 9 BM, 10 BM, 12 BM, 13 BM, 20 BM and 20 ID. Significant time is spent on hands-on instruction in data processing and data analysis using Feff, Ifeffit and Athena & Artemis.

Updates

A Poster is available for the 2009 APS XAFS School. PDF, JPEG

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Lectures

Beamline Instruction

Dates and deadlines

Date

Deadline

3/16/09

Application site opens

5/11/09

Last day to apply/register for the course

5/21/09

Acceptance letters sent by email

6/6/09

Last day to reserve room at Argonne Guest House

6/19/09

Tuition due

07/06/09, 9:00 am

School begins

07/10/09, noon

School ends

Program

Monday July 6

Abstract

8:00 am

APS User Training, as needed

APS User Office

9:00 am

Welcome[1]

Murray Gibson

9:15 am

Safety Briefing

Paul Rossi

9:20 am

Overview

Scott Calvin

A XAFS spectrum cannot be directly turned into structural information--some more clever analysis technique must be employed. There are four broad approaches that are commonly used: fingerprinting, linear combination analysis, principal component analysis, and modelling. This presentation will introduce the four techniques and talk about their relative strengths and weaknesses, as well as consider the kinds of questions that can be addressed by analyzing XAFS.

10:30 am

Coffee Break

10:45 am

Experiment/Beamline/Detectors

Jeremy Kropf

The beamlines and optics talk will give basic overviews of: Types of synchrotron sources and spectra properties, requirements for XAFS, beamline optics, and detectors for XAFS.

12:00 pm

Group Photo (402 Main Entrance) followed by Lunch (402 Gallery)

1:00 pm

Sector specific orientation

beamline staff, at beamlines

1:30 pm

Data collection

beamline staff

6:00 pm

Dinner (Argonne Guest House)[2]

7:00 pm

Overnight data collection

by arrangement

Tuesday July 7

Abstract

8:30 am

Sample Preparation

Grant Bunker

9:30 am

EXAFS Theory

Matt Newville

presentation of fundamentals of absorption (if not covered in an overview) through a simple development of the EXAFS equation, what Feff calculates (not how, but some on what pieces go into it), multiple scattering, and why the EXAFS equation breaks down for XANES.

10:45 am

Coffee Break

11:00 am

Basics of data processing, Athena

Shelly Kelly

ppt presentation using screen shots to show how to process data in athena. Includes reading data into athena, calibration, aligning, merging, FT. The talk will cover the basic concepts of data processing and how they are implemented in Athena.

12:00 pm

Lunch (402 Gallery)

1:00 pm

Data collection

beamline staff

6:00 pm

Dinner (Argonne Guest House)[2]

7:00 pm

Overnight data collection

by arrangement

Wednesday July 8

Abstract

8:30 am

XANES

Serena DeBeer George

An introduction to X-ray absorption near edge spectroscopy will be presented, with a focus on metal K-, metal L-, and ligand K-edge spectra. The geometric and electronic structural parameters which govern spectroscopic changes will be discussed, with an emphasis on the use of XANES spectra as a complementary tool for EXAFS analysis.

9:45 am

Demo: Linear Combination Fitting

Bruce Ravel

This demonstration uses Athena to perform Linear Combination Fitting (LCF) on a time series of measurements made as Gold (III) Chloride is reduced to metallic gold through by interaction with a cyanobacteria culture. The LCF results are used to determine a rate constant for the reaction and to uncover an intermediate stage in the reaction. This demo is a truncated version of the work published as Environ. Sci. Technol., 2006, 40 (20), pp 6304–6309.
Athena project file with data from Bruce's example

10:45 am

Coffee Break

11:00 am

Demo: Principal Component Analysis

Scott Calvin

This combination of presentation and demonstration will use Athena and SixPack to show how principal component analysis (PCA) can be a key part of a XAFS analysis. The particular system studied will be a set of nanoparticles designed to have iron cores surrounded by gold shells.
Zip file with data for Scott's example

12:00 pm

Lunch (402 Gallery)

1:00 pm

Basics of Data Analysis

Shelly Kelly

ppt presentation using screen shots of Artemis to show how to run atoms, and Feff. How to read in data, set parameters and set up a fit and look at the results. This talk will cover the basic concepts of data analysis and how they are implemented in Artemis.

2:15 pm

Coffee Break

2:30 pm

Demo: First and Second Shell Fitting

Matt Newville

Demo of Fe-O (rock-salt structure) fit, first and second shell. Can be done in 45 minutes.

3:45 pm

Open Data Analysis Lab

Instructors

6:00 pm

Dinner (Reza's Persian Restaurant)[3]

Thursday July 9

Abstract

8:30 am

Other Techniques

Serena DeBeer George

9:30 am

Advanced EXAFS Modeling Strategies

Bruce Ravel

The EXAFS spectrum is often rich in information about the details of the local atomic configuration much beyond what can be determined by simple, first-shell, single-scattering data analysis. Ifeffit and Artemis implement many tools for getting the most out of your EXAFS data — including constraints and restraints, multiple k-weight fitting, and multiple data set fitting. This presentation presents an overview of these advanced analysis techniques along with a discussion of statistics and information in the EXAFS measurement.

10:30 am

Coffee Break

10:45 am

Demo: How to Tell Fe-O From Fe-S

Scott Calvin

Zip file with data from Scott's example

12:00 pm

Lunch (402 Gallery)

1:00 pm

Demo: How to Tell Fe-O From Fe-S, Continued

Instructors/Scott Calvin

During the afternoon session, everyone will work through Fe-O and Fe-S data.

2:15 pm

Demo: Methyltin Chloride

Bruce Ravel

This demonstration uses Artemis to explain the use of multiple k-weight and multiple data set fitting to deal with a fitting problem with severely constrained information content. This demo also shows one strategy for preparing a Feff calculation for a non-crystalline material. This demo is related to work published as J. Environ. Monit., 2007, 9, 358 - 365.
Methyl Tin data as an Athena project file
Dimethyl tin dichloride structure
Dimethyl tin dichloride Feff input file

3:30 pm

Coffee Break

3:45 pm

Open Data Analysis Lab

Instructors

6:00 pm

Dinner (Aodake Japanese Restaurant)[3]

Friday July 10

Abstract

9:00 am

Demo: Fe-Ni-S

Matt Newville

Artemis (perhaps SixPack) demo of fit of Ni K edge in Fe75Ni5S20 and Fe75Ni5Si20: how to hack a Feff file to change atom type, and compare Ni as a dopant in bcc Fe vs. Ni in nickel silicide.

10:30 am

Coffee Break

10:45 am

How to write a GUP and a Manuscript

Bruce Ravel

XAFS beamlines are a limited resource. Many of these beamlines are oversubscribed at the APS and at synchrotrons around the world. It is important, therefore, to write a strong General User proposal that will impress the review panel and increase your chances of obtaining beamtime. Bruce is the chair of the APS XAS proposal review panel and a member of review panels at two other synchrotrons. Giving advice on good manuscript writing is much more difficult, but the second part of the talk will cover some useful dos and don'ts for XAFS manuscript writing.

11:45 pm

School Ends

12:00 pm

Lunch (402 Gallery)

12:00 pm

APS User Science Seminar (401/A1100)

TBA

TBA

  1. All lectures and tutorials will be held in APS Building 402 Room E1100-1200, which is located at the rear of the 402 Auditorium.
  2. Dinners for Monday and Tuesday, during the Data Collection part of the program, are at the Argonne Guest House. Participants and Instructors should identify themselves as part of the XAFS School when signing the check.
  3. The bus for Reza's and Aodake dinners will depart from the APS around 6 pm, and will make a brief stop at the ANL Guest House before heading off site.



Workshops/APS2009 (last edited 2009-10-15 16:37:47 by MattNewville)