Diffraction Changes¶

Powder Diffraction¶

• New loader LoadILLDiffraction has been added to load the data-scan nexus files from ILL diffractometers.
• ISIS Powder diffraction scripts have been released. These include support for GEM, PEARL and POLARIS instruments. For more details see the ISIS Powder documentation under API, Python category.
• New instrument definition files are added for D1B, D4, and D20 powder/liquid diffractometers at ILL. The source and monitor positions, as well as detector to sample distance have been corrected for existing D2B.
• New IDF for the POWGEN upgrade
• AlignAndFocusPowder Now supports supplying an a second .cal file for the GroupingFilename.
• New algorithm AlignAndFocusPowderFromFiles is a wrapper around AlignAndFocusPowder which supports caching results. SNSPowderReduction and PDToPDFgetN have been reworked to take advantage of this.
• Bugfix in SNAPReduce with loading previous normalizations
• SNSPowderReduction now supports splitters in format of MatrixWorkspace and general TableWorkspace.
• A new NOMAD instrument definition file with corrected values.
• Add default sample logs names of wavelength and frequency to PDDetermineCharacterizations for Vulcan.

Single Crystal Diffraction¶

• PredictPeaks v1 has a new option PredictPeaksOutsideDetectors which will predict peaks which fall outside of any defined detectors. This feature requires an extended detector space definition and will do nothing if this is not present in the IDF.
• PredictPeaks v1 and FindPeaksMD v1 have a new option EdgePixels which will not predict or find peaks which fall in the input number of pixels from the edge of detectors.
• StartLiveData will load “live” data streaming from MaNDi data server.
• PDCalibration is better at giving out physically meaningful results. It will no longer create calibrations that will convert time-of-flight to negative or imaginary d-spacing.
• SaveIsawPeaks now saves the calibration data for all detector banks in instrument so the header may be longer
• LoadIsawPeaks now uses the calibration lines to calibrate the detectors banks for CORELLI
• SCD_Event_Data_Reduction_Interface and SCD_Reduction python scripts work with both nxs and h5 extensions for data file.
• New algorithm IntegrateEllipsoidsTwoStep v1 which can be used to integrate weak peaks by using parameters derived from strong peaks.
• FindSxPeaks Resolved an issue where the algorithm failed on instruments with multiple detectors per spectrum.
• A new HB3A instrument definition file, for its 512 x 512 detector, is created. Its valid period is from February 2017 to late April 2017.
• An IDF for HB3A with 256 by 256 detectors was created. It was dated from late April 2017 because its original detector has been switched back.
• A Bug fix was added to the WISH instrument parameter file to prevent predicted peaks falling between tube gaps.
• New algorithm DeltaPDF3D for calculating the 3D-deltaPDF from a HKL MDHistoWorkspace
• Resolved an issue with instrument viewer where the instrument could not be viewed in 3D mode with the new IDF for wish.
• HB3A reduction interface (application) now supports to integrate single crystal peaks by fitting peak intensity with 2D Gaussian with more detailed integraton information for user.

Full list of diffraction and imaging changes on GitHub.