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Ice rings: Difference between revisions
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* Please see [[Wishlist#Would be nice to have]]: there's a list of additional (high-) resolution ranges one might want to exclude (in [[CORRECT]]). | * Please see [[Wishlist#Would be nice to have]]: there's a list of additional (high-) resolution ranges one might want to exclude (in [[CORRECT]]). | ||
* A currently possible way to prevent ice rings from spoiling the [[IDXREF]] step is to set "TRUSTED_REGION=0 X" for INIT, where X is calculated such that ice rings are excluded. Using Bragg's law and an approximation, we find that <br /> X = <math>\frac{Wavelength \cdot Distance} { | * A currently possible way to prevent ice rings from spoiling the [[IDXREF]] step is to set "TRUSTED_REGION=0 X" for INIT, where X is calculated such that ice rings are excluded. Using Bragg's law and an approximation, we find that <br /> X = <math>\frac{Wavelength \cdot Distance} {4 \cdot NX \cdot QX}</math> should give approx. 4 Å cutoff, which should exclude all ice rings. <br /> Drawback: after successful indexing, INIT needs to be re-run with "TRUSTED_REGION=0 1.05" or so. | ||
A potential pitfall: the above assumes that the direct beam position is near the middle of the detector. | A potential pitfall: the above assumes that the direct beam position is near the middle of the detector. | ||
* Please see [[Optimization]] for how to treat remaining ice reflections showing up as "aliens" in [[CORRECT.LP]]. | * Please see [[Optimization]] for how to treat remaining ice reflections showing up as "aliens" in [[CORRECT.LP]]. | ||