6.4

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LoadDNSEvent v1

../_images/LoadDNSEvent-v1_dlg.png

LoadDNSEvent dialog.

Summary

Loads data from the DNS PSD detector to a Mantid EventWorkspace.

Properties

Name Direction Type Default Description
InputFile Input string Mandatory A DNS mesydaq listmode event datafile. Allowed extensions: [‘.mdat’]
ChopperChannel Input j 2 The Chopper Channel (1 to 4)
NumberOfTubes Input j 128 The number of tubes, each tube has 1024 pixels (1 to 128)
DiscardPreChopperEvents Input boolean True Discards events before first chopper trigger (turn off for elastic)
SetBinBoundary Input boolean True Sets all bin boundaries to include all events (can be turned off to save time).
OutputWorkspace Output EventWorkspace Mandatory The name of the output workspace.

Description

This algorithm loads a DNS mesytec psd listmode file into an EventWorkspace, it does not load the instrument definition.

Output

EventWorkspace with the X-axis in the Time-of-flight units.

ChopperChannel The chopper input channel as set in mesydaq gui. It can be set to integers between 1 and 4. At DNS default is 2.

NumberOfTubes The number of tubes of the detector, each tube has 1024 pixels. The full detector at DNS has 128 tubes. It can be set to integers between 1 and 128.

DiscardPreChopperEvents: If set to true events with a timestamp before the first chopper timestamp are ignored, since they have no valid TOF. If the dataset is elastic they can be included, since only the position and not the TOF is used.

SetBinBoundary: If set to true the bin boundaries of the spectrum histrograms are set to include all events in one bin (0 to maximum TOF). It can be turned off for faster loading, then the histograms are empty, with both boundaries close to 0. The binning can then later be reproduced by applying Rebin with the paraemter Params=‘0, {0}, {0}’.format(eventWS.getTofMax()).

Restrictions

  • This algorithm only supports the DNS instrument.
  • This algorithm loads raw TOF data, without normalization and without considering the detectorbank position.

Usage

Example 1 - Load TOF PSD data:

eventWS = LoadDNSEvent(InputFile="DNS_psd_150c_first_tube.mdat", ChopperChannel='2', NumberOfTubes='1')
print("Number of events: {}".format(eventWS.getNumberEvents()))
print("Maximum time of flight: {}".format(eventWS.getTofMax()))
print("Number of detector pixels: {}".format(eventWS.getNumberHistograms()))
print("Number of bins: {}".format(eventWS.blocksize()))

# rebin spectra:
test2 = Rebin(InputWorkspace='eventWS', Params='0, 100, {0}'.format(eventWS.getTofMax()))
print("Number of bins after rebinning: {}".format(test2.blocksize()))

Output:

 Number of events: 184
 Maximum time of flight: 6641.4
 Number of detector pixels: 1024
 Number of bins: 1
 Number of bins after rebinning: 67

Categories: AlgorithmIndex | DataHandling

Source

C++ header: LoadDNSEvent.h

C++ source: LoadDNSEvent.cpp