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Mar. 24, 2017

* Cheetah has peak finder that is used a lot in crystallography
* Question of how to validate beam center finding algorithm and detector geometry
* bad pixels: after strong bragg peak the pixel might be temporarily damanged and should be masked out for consecutive shots until it recovers

## Reasons for rerunning data
* Anton Barty, Tom, Alexander (CFEL)
* poor detector calibration
* if results are not obvious to confirm if algorithm is working
* spectroscopy if detector corrections are required
* jet streaks for angular integration
* wrong event code triggereing, confirming that pump laser was running, backup diagnostic
* parameter tuning for example for peak finding
* hitfinding mostly works on first pass -> 10 times data reduction, indexing multiple times
* wrong hitfinding might bias physics
* if there is not enough data so hitfinding is important to really get all hits
* reprocessing data with new algorithms
* reliable gain maps for detectors (escpecially for high intensity), nonlinear detector response
* diffuse scattering requires whole image

* Peter Schwander
* veto signal for SPI for non hits, real time hitfinding
* convert data to single photons

* Filipe Maia
* detector artifacts
* signal influences gain for pnccd and cspad
* hitfinding can be diffcult for single protein SPI, because signal is very weak
* use ion tof or other hardware tools for hitfinding

* Mariano Trigo
* time tool calibration important for cube

* Ti-Yen
* halo close to beamcenter makes hitfinding diffcult for SPI
* converting ADU to photons is sufficient for SPI

* Aaron Brewster
* reprocessing because of unkown crystal unit cell
* unit cell can drift during the experiment, depending on sample preperation

* Peter Zwart
* hitrate can be quite high for imaging can be up to 80%
* clustering algorithm for hitfinding
* stable beam and sample delivery required
* difficulties in converting ADU to photons for pnccd, rounding errors
* check photon conversion on simulated data, understand errors in conversion

Feb. 22, 2017

Link to slides: 

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