John BargarJohn BargarSenior ScientistSenior ScientistJune 30, 2011June 30, 2011

SSRL Synchrotron X-Ray Absorption Spectroscopy Summer School (6th annual)

June 28 - July 1, 2011

Intro to Sixpack, Background Subtraction

0 1 2 3 4-15

-10

-5

0

5

10

15

U LIII

edge

data at 298 K fit

FT

of k3

(k)

r (Å)

Bacteria

1. Install SixPack by extracting zip file

2. Start SixPack

3. Review All Modules

4. SamView basics• Opening data: SG1UC click on each file• Plotting data: plot options, zoom/unzoom, coordinates• Derivatives and E calibration• Applying E shifts to data BEWARE: ONLY THE FIRST SCAN COUNTS!• Save averages: muF, muT1• WHICH DATA SET SHOULD I USE, TRANS OR FLUO?• Best way to get data for plotting

Intro to SixPack

5. Open SG1UG files (leave other files there)

6. Group ave with muF

7. Delete SG1UC files

8. Save muF

9. Energy calibration – CAREFUL!

10. Save and Clear

11. Open EXP08_6_1EXT_EXAFS_002 files

12. Inspect and DT correct. 13. Save muF

Intro to SixPack

1. Start a NEW sixpack session.

2. Background subtraction basics• Open files with .avg extensions • Plotting data: plot options, zoom/unzoom, coordinates• Derivatives and E calibration• Applying E shifts to data THIS IS THE SAFER WAY TO RECALIBRATE!• Where are the XANES?• Where are the EXAFS?• What is the best spline?• How to take the FT• Saving Data for XANES• Saving Data for EXAFS•

Intro to Background Removal