2. The New X-Ray Guy 1. Frankenthal / Mannheim 2. La Chapelle Aux Bois 3. Kasierslautern 4. Göttingen Peter MüllerPeter Mueller

3. The New X-Ray Guy

4. The New Cryostream

5. Judging the Quality of a Crystal. Determining the Best Exposure Time. Data Collection Strategy. And now: Some Crystallography

6. Initial Immages Judging the Quality of the X-tal Take two immages 90° appart.

7. The Rocking Curve Judging the Quality of the X-tal Analyze Rocking Number of frames in both directions Size of the box halfwidth = mosaicity

8. Compare two (or more) immages that differ only in exposure time. Does a longer exposure time add information to the immage? Determining the Exposure Time File Display 10 second frame File Display 20 second frame Analyze Contrast File Display 30 second frame Analyze Contrast

9. Determining the Exposure Time 20 seconds is better than 10 seconds. 30 seconds not better than 20 sconds. Our exposure time is 20 seconds per frame. Always collect a new dark current at your exposure time or at least load an older (but not too old!) dark current taken at your exposure time. compare

10. Collect Dark Current Detector Dark Current Now you are ready for data collection What is the best strategy?

11. The Platform Geometry omega phi

12. phi- and omega-scans Incident beam Detector Diffracted beam hkl reflection Reciprocal lattice hkl lattice planes Crystal hkl reciprocal lattice point s s Q C O P d    Ewald sphere with radius r = 1/ Phi-scans at different omega-angles Omega-scans at different phi-angles phi- and omega-scans are orthogonal...try to combine them!

13. Collect Dark Current Edit Multi Run Three 200° omega-scans and two 360° phi-scans Two 200° omega-scans and one 360° phi-scan that‘s plenty for any situation. is enough for mmm and higher.

14. The Zero-Frames

16. We have a new HOMEPAGE http://web.mit.edu/x-ray

17. Next Meeting Tuesday November 9, 11:00 a.m. AMDUR room (here) Data Reduction with SAINT and SADABS