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EnggCalibrate v1

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Summary

This algorithm is deprecated as of May 2021, consider using PDCalibration instead.Calibrates one or more detector banks (or group(s) of detectors) by performing single peak fitting.

See Also

EnggCalibrateFull

Properties

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	Workspace with the calibration run to use.
ExpectedPeaks	Input	dbl list	1.1046,1.35285,1.6316,1.91322,2.7057	A list of dSpacing values where peaks are expected.
ExpectedPeaksFromFile	Input	string		Load from file a list of dSpacing values to be translated into TOF to find expected peaks. This takes precedence over ‘ExpectedPeaks’ if both options are given. Allowed extensions: [‘.csv’]
VanadiumWorkspace	Input	MatrixWorkspace		Workspace with the Vanadium (correction and calibration) run. Alternatively, when the Vanadium run has been already processed, the properties can be used
VanIntegrationWorkspace	Input	TableWorkspace		Results of integrating the spectra of a Vanadium run, with one column (integration result) and one row per spectrum. This can be used in combination with OutVanadiumCurveFits from a previous execution and VanadiumWorkspace to provide pre-calculated values for Vanadium correction.
VanCurvesWorkspace	Input	MatrixWorkspace		A workspace2D with the fitting workspaces corresponding to the instrument banks. This workspace has three spectra per bank, as produced by the algorithm Fit. This is meant to be used as an alternative input VanadiumWorkspace for testing and performance reasons. If not given, no workspace is generated.
Bank	Input	string		Which bank to calibrate. It can be specified as 1 or 2, or equivalently, North or South. See also SpectrumNumbers for a more flexible alternative to select specific detectors. Allowed values: [‘’, ‘North’, ‘South’, ‘Both: North, South’, ‘1’, ‘2’]
SpectrumNumbers	Input	string		Sets the spectrum numbers for the detectors that should be considered in the calibration (all others will be ignored). This option cannot be used together with Bank, as they overlap. You can give multiple ranges, for example: “0-99”, or “0-9, 50-59, 100-109”.
DetectorPositions	Input	TableWorkspace		Calibrated detector positions. If not specified, default ones (from the current instrument definition) are used.
OutputParametersTableName	Input	string		Name for a table workspace with the calibration parameters calculated from this algorithm: difc and zero parameters for GSAS. these two parameters are added as two columns in a single row. If not given, no table is generated.
DIFA	Output	number		Calibration parameter DIFA for the bank or range of pixels/detectors given
DIFC	Output	number		Calibration parameter DIFC for the bank or range of pixels/detectors given
TZERO	Output	number		Calibration parameter TZERO for the bank or range of pixels/detectors given
FittedPeaks	Output	TableWorkspace	Mandatory	Information on fitted peaks as produced by the (child) algorithm EnggFitPeaks.

Description

Warning

This algorithm is being developed for a specific instrument. It might get changed or even removed without a notification, should instrument scientists decide to do so.

Utilises EnggFocus v1 which performs a TOF to dSpacing conversion using calibrated pixel positions, focuses the values in dSpacing and then converts them back to TOF. EnggFocus v1 also perform corrections with Vanadium data.

Then this algorithm calls EnggFitPeaks v1 (as a child algorithm) which through a sequence of peak fits determines a linear relationship between dSpacing and measured TOF values in terms of DIFA, DIFC and TZERO values and provides the these parameters to the Calibrate algorithm.

This algorithm provides an indirect calibration of the sample position, that is, a calibration returned in terms of DIFA, DIFC and ZERO rather than an actual new sample position (hence the reason for ‘indirect’).

The parameters DIFA, DIFC and ZERO are returned and can be retrieved as output properties as well. If a name is given in OutputParametersTableName the algorithm also produces a table workspace with that name, containing the two output parameters. Presently the DIFA parameter is always set to zero (see EnggFitTOFFromPeaks v1).

See the algorithm EnggFocus v1 for details on the Vanadium corrections.

Categories: AlgorithmIndex | Diffraction\Engineering

Source

Python: EnggCalibrate.py

Usage

Note

To run these usage examples please first download the usage data, and add these to your path. In Mantid this is done using Manage User Directories.

Example - Calculate Difa, Difc, and Zero for EnginX:

out_tbl_name = 'out_params'
ws_name = 'test_engg_data'
Load('ENGINX00213855.nxs', OutputWorkspace=ws_name)

# Using precalculated Vanadium corrections. To calculate from scrach see EnggVanadiumCorrections
van_integ_ws = Load('ENGINX_precalculated_vanadium_run000236516_integration.nxs')
van_curves_ws = Load('ENGINX_precalculated_vanadium_run000236516_bank_curves.nxs')

difa1, difc1, tzero1, peaks1 = EnggCalibrate(InputWorkspace=ws_name,
                                    VanIntegrationWorkspace=van_integ_ws,
                                    VanCurvesWorkspace=van_curves_ws,
                                    ExpectedPeaks=[1.09, 1.28, 2.1], Bank='1',
                                    OutputParametersTableName=out_tbl_name)

difa2, difc2, tzero2, peaks2 = EnggCalibrate(InputWorkspace=ws_name,
                                    VanIntegrationWorkspace=van_integ_ws,
                                    VanCurvesWorkspace=van_curves_ws,
                                    ExpectedPeaks=[1.09, 1.28, 2.1], Bank='2')
tbl = mtd[out_tbl_name]
print("The output table has {0} row(s)".format(tbl.rowCount()))

Output:

The output table has 1 row(s)