PhaseQuad dialog.
Table of Contents
This algorithm provides a method for combining signals from multiple detector segments to form two output signals in quadrature phase. It is of particular use when working with muon spin rotation signals measured using highly segmented detector arrays that are typically found at pulsed muon sources (ISIS has instruments with up to 600 detector elements). The method allows information from individual detectors to be combined in a way that makes full use of the dataset.
This algorithm is frequently run as a precursor to making a Rotating Reference Frame transformation of the dataset using the algorithm RRFMuon v1. Both algorithms are fully described in the article by T.M. Riseman and J.H. Brewer [Hyp. Int., 65, (1990), 1107].
| Name | Direction | Type | Default | Description |
|---|---|---|---|---|
| InputWorkspace | Input | MatrixWorkspace | Mandatory | Name of the input workspace containing the spectra |
| OutputWorkspace | Output | MatrixWorkspace | Mandatory | Name of the output workspace to hold squashograms |
| PhaseTable | Input | TableWorkspace | Name of the Phase Table | |
| PulseOver | Input | number | 60 | Bin number when the pulse is over. Mandatory if PhaseTable is provided |
| MeanLag | Input | number | 127.702 | Average Lag value over detectors |
| DoublePulse | Input | boolean | False | If signal is double-pulse |
| PhaseList | Input | string | A space-delimited text file with a six-row header. Allowed extensions: [‘.inf’] |
Assuming that the InputWorkspace contains measured counts as a function of time, the algorithm returns a workspace containing two spectra (squashograms) as a function of the same time binning. Either PhaseList or PhaseTable must be provided. Note: The first column is ignored in both cases.
PhaseList is expected to have a six-row header, including overall information, and 6 columns:
PhaseTable is expected to have four columns:
Note
To run these usage examples please first download the usage data, and add these to your path. In MantidPlot this is done using Manage User Directories.
Example - Computing squashograms from PhaseList:
# Load a set of spectra from a EMU file
ws = LoadMuonNexus('emu00006473.nxs')
# Create a PhaseList file with some arbitrary detector information
import os
phaselist_path = os.path.join(os.path.expanduser("~"),"PhaseList.txt")
phaselist_file = open(phaselist_path,'w')
phaselist_file.write("MuSR\n")
phaselist_file.write("Dummy line\n")
phaselist_file.write("Dummy line\n")
phaselist_file.write("Dummy line\n")
phaselist_file.write("Dummy line\n")
phaselist_file.write("32 0 60 0.0\n")
for i in range(0,16):
phaselist_file.write("1 50.0 0.00 0 0 1\n")
phaselist_file.write("1 50.0 1.57 0 0 1\n")
phaselist_file.close()
ows = PhaseQuad(InputWorkspace='ws',PhaseList=phaselist_path)
print "Output workspace contains", ows.getNumberHistograms(), "histograms"
Output:
Output workspace contains 2 histograms
Example - Computing squashograms from PhaseTable:
# Load a set of spectra from a EMU file
ws = LoadMuonNexus('emu00006473.nxs')
# Create a PhaseTable with some arbitrary detector information
tab = CreateEmptyTableWorkspace()
tab.addColumn('bool', 'Status')
tab.addColumn('double', 'Asymmetry')
tab.addColumn('double', 'Phase')
tab.addColumn('double', 'DeadTime')
for i in range(0,16):
tab.addRow([1, 50.0, 0.00, 0])
tab.addRow([1, 50.0, 1.57, 0])
ows = PhaseQuad(InputWorkspace='ws',PhaseTable='tab')
print "Output workspace contains", ows.getNumberHistograms(), "histograms"
Output:
Output workspace contains 2 histograms
Categories: Algorithms | Muon