Automated sorting of high repetition rate coherent diffraction data from XFELS
Description
'Coherent X-rays are routinely provided today by the latest Synchrotron and X-ray Free-electron Laser Sources. When these diffract from a crystal containing defects, interference leads to the formation of a modulated diffraction pattern called ''spec
Detailed example
'Coherent X-rays are routinely provided today by the latest Synchrotron and X-ray Free-electron Laser Sources. When these diffract from a crystal containing defects, interference leads to the formation of a modulated diffraction pattern called ''speckle''. When the defects move around, they can be quantified by a correlation analysis technique called X-ray Photon Correlation Spectroscopy. But the speckles also change when the beam moves on the sample. By scanning the beam in a controlled way, the overlap between the adjacent regions gives redundancy to the data, which allows a solution of the inherent phase problem. This is the basis of the coherent X-ray ptychography method which can achieve image resolutions of 10nm, but only if the probe positions are known. The goal of this proposal will be to separate ''genuine'' fluctuations of a material sample from the inherent beam fluctuations at the high data rates of XFELs. Algorithms will be developed to calculate the correlations between
AI / analytics pattern
Classical/Predictive Machine Learning: Models trained on data to make predictions or classifications based on identified patterns or relationships.
Automation level / stage
a) Pre-deployment – The use case is in a development or acquisition status.
Expected benefit
'Coherent X-rays are routinely provided today by the latest Synchrotron and X-ray Free-electron Laser Sources. When these diffract from a crystal containing defects, interference leads to the formation of a modulated diffraction pattern called ''speckle''. When the defects move around, they can be quantified by a correlation analysis technique called X-ray Photon Correlation Spectroscopy. But the speckles also change when the beam moves on the sample. By scanning the beam in a controlled way, the overlap between the adjacent regions gives redundancy to the data, which allows a solution of the inherent phase problem. This is the basis of the coherent X-ray ptychography method which can achieve image resolutions of 10nm, but only if the probe positions are known. The goal of this proposal will be to separate ''genuine'' fluctuations of a material sample from the inherent beam fluctuations at the high data rates of XFELs. Algorithms will be developed to calculate the correlations between all the coherent diffraction patterns arriving in a time series, then used to separate the two sources of fluctuation using the criterion that the ''natural'' thermal fluctuations do not repeat, while beam ones do. We separate the data stream into image and beam ''modes'' automatically.'
Audit / financial statement impact
Does not meet definition
Controls / human review
ATO: Not reported; PIA: Not published
Data needed
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