The New X-Ray Guy1. Frankenthal / Mannheim2. La Chapelle Aux Bois3. Kasierslautern4. GttingenPeter MllerPeter Mueller

The New X-Ray Guy

The New Cryostream

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

Initial ImmagesJudging the Quality of the X-talTake two immages 90 appart.

The Rocking CurveJudging the Quality of the X-talNumber of frames in both directionsSize of the boxhalfwidth =mosaicity

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

Determining the Exposure Time20 seconds is better than 10 seconds.

30 seconds not better than 20 sconds.

Our exposure time is20 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

Collect Dark CurrentNow you are ready for data collectionWhat is the best strategy?

The Platform Geometry

phi- and omega-scansPhi-scans at different omega-anglesOmega-scans at different phi-anglesphi- and omega-scans are orthogonal...try to combine them!

Collect Dark CurrentThree 200 omega-scansand two 360 phi-scansTwo 200 omega-scansand one 360 phi-scanthats plenty forany situation.is enough for mmm and higher.

The Zero-Frames

The Zero-Frames

We have a new HOMEPAGEhttp://web.mit.edu/x-ray

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