CombineDiffCal v1

Summary

Combine a per-pixel calibration with a grouped spectrum calibration

Properties

Name

Direction

Type

Default

Description

PixelCalibration

Input

TableWorkspace

Mandatory

DiffCal TableWorkspace that will be updated. This is often generated from cross-correlation. These are the “prev” values in the documentation.

GroupedCalibration

Input

TableWorkspace

Mandatory

DiffCal table generated from calibrating grouped spectra. This is the “DIFCpd” value in the documentation.

CalibrationWorkspace

Input

MatrixWorkspace

Mandatory

Workspace where conversion from d-spacing to time-of-flight for each spectrum is determined from. This is the “DIFCarb” value in the documentation.

OutputWorkspace

Output

TableWorkspace

Mandatory

DiffCal table generated from calibrating grouped spectra

MaskWorkspace

Input

MaskWorkspace

MaskedWorkspace for PixelCalibration

Description

This algorithm combines pixel calibration results (prev subscript below) from the PixelCalibration workspace with the calibration of focussed data from PDCalibration (pd subscript below). The arb subscript below denotes values found in the CalibrationWorkspace. This is part of the larger workflow for powder diffraction calibration.

Warning

The GroupedCalibration table is assumed to not have DIFA or TZERO set.

Input arguments

  • PixelCalibration is the previous calibration result

    • Has values for each detector pixel

    • Provides DIFCprev, DIFAprev, and TZEROprev

  • GroupedCalibration

    • Has values for each detector pixel, but the values are generally the same within a focused group

    • Provides DIFCpd

    • Is the OutputCalibrationTable from previous PDCalibration execution

  • CalibrationWorkspace

    • Has values for each spectrum which are grouped pixels

    • Provides DIFCarb

    • Is the InputWorkspace from previous PDCalibration execution

How values are combined

The effective calibration values are calculated using the following equations

DIFCeff=DIFCpdDIFCarbDIFCprev

where DIFCpd is from PDCalibration, DIFCarb is found in the parameter CalibrationWorkspace that was the input workspace to PDCalibration, and DIFCprev is from the previous calibration. The value of TZERO is unchanged

TZEROeff=TZEROprev

The value of DIFA is updated by

DIFAeff=(DIFCpdDIFCarb)2DIFAprev

If pixels are masked in MaskWorkspace, missing from PixelCalibration, or missing from the list of contributing pixels in CalibrationWorkspace, then the calibration constants found in GroupedCalibration will be copied.

Categories: AlgorithmIndex | Diffraction\Utility

Source

C++ header: CombineDiffCal.h

C++ source: CombineDiffCal.cpp