OSIRISDiffractionReduction dialog.
Table of Contents
This Python algorithm performs the operations necessary for the reduction of diffraction data from the Osiris instrument at ISIS into dSpacing, by correcting for the monitor and linking the various d-ranges together.
| Name | Direction | Type | Default | Description |
|---|---|---|---|---|
| Sample | Input | str list | The list of run numbers that are part of the sample run. There should be five of these in most cases. Enter them as comma separated values. | |
| Vanadium | Input | str list | The list of run numbers that are part of the sample run. There should be five of these in most cases. Enter them as comma separated values. | |
| Container | Input | string | Run for the container | |
| ContainerScaleFactor | Input | number | 1 | Factor by which to scale the container |
| CalFile | Input | string | Mandatory | Filename of the .cal file to use in the [[AlignDetectors]] and [[DiffractionFocussing]] child algorithms. |
| SpectraMin | Input | number | 3 | Minimum Spectrum to Load from (Must be more than 3) |
| SpectraMax | Input | number | 962 | Maximum Spectrum to Load from file (Must be less than 962) |
| OutputWorkspace | Output | MatrixWorkspace | Mandatory | Name to give the output workspace. If no name is provided, one will be generated based on the run numbers. |
| LoadLogFiles | Input | boolean | True | Load log files when loading runs |
| DetectDRange | Input | boolean | True | Disable to override automatic dRange detection |
| DRange | Input | number | 1 | Drange to use when DetectDRange is disabled |
Performs a diffraction reduction for OSIRIS using normalisation to a set of vanadium sample runs.
The dRanges are numbered as per the OSIRIS manual. Otherwise the dRange is determined based on the table provided in the manual.
Example - Running OSIRISDiffractionReduction.
import os
def createDummyOSIRISWorkspace(name, func, xmin, xmax, bin_width):
"""Creates a workspace that looks something like an OSIRIS diffraction run"""
#create workspace according to function
ws = CreateSampleWorkspace("Histogram", Function="User Defined", UserDefinedFunction=func, XMin=xmin, XMax=xmax, Random=True, BinWidth=bin_width, NumBanks=11, OutputWorkspace=name)
ws = CropWorkspace(ws, StartWorkspaceIndex=0, EndWorkspaceIndex=1009, OutputWorkspace=name)
AddSampleLog(ws, 'gd_prtn_chrg', '30.01270866394043', 'Number')
#load instrument parameters
LoadInstrument(ws, RewriteSpectraMap=True, InstrumentName='OSIRIS')
param_file = config['instrumentDefinition.directory'] + 'OSIRIS_diffraction_diffspec_Parameters.xml'
LoadParameterFile(ws, Filename=param_file)
return ws
#create two dummy workspaces with one peak
function = "name=Lorentzian, Amplitude=350000,PeakCentre=40000, FWHM=80"
ws1 = createDummyOSIRISWorkspace('ws1', function, 1.17e+04, 5.17e+04, 4.7)
ws2 = createDummyOSIRISWorkspace('ws2', function, 29400, 69400, 16.1)
#create two vanadium runs
function = "name=FlatBackground, A0=10"
van1 = createDummyOSIRISWorkspace('van1', function, 1.17e+04, 5.17e+04, 4.7)
van2 = createDummyOSIRISWorkspace('van2', function, 29400, 69400, 16.1)
samples = [ws1.name(), ws2.name() ]
vanadium = [van1.name(), van2.name()]
#OSIRISDiffractionReduction currently only support loading from file.
for ws in (samples + vanadium):
path = os.path.join(os.path.expanduser("~"), ws + ".nxs")
SaveNexus(ws, path)
#run OSIRISDiffractionReduction
samples = [os.path.join(os.path.expanduser("~"), sample + ".nxs") for sample in samples]
vanadium = [os.path.join(os.path.expanduser("~"), van + ".nxs") for van in vanadium]
ws = OSIRISDiffractionReduction(Sample=','.join(samples), Vanadium=','.join(vanadium), CalFile="osiris_041_RES10.cal")
print "Number of Spectra: %d, Number of bins: %d" % (ws.getNumberHistograms(), ws.blocksize())
Output:
Number of Spectra: 1, Number of bins: 7582
Categories: Algorithms | Diffraction\Reduction
Python: OSIRISDiffractionReduction.py