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## Summary¶

Loads SNS raw neutron event data format and stores it in a workspace.

This algorithm is also known as: LoadEventPreNeXus2

## Properties¶

Name

Direction

Type

Default

Description

EventFilename

Input

string

Mandatory

The name of the neutron event file to read, including its full or relative path. In most cases, the file typically ends in neutron_event.dat (N.B. case sensitive if running on Linux). Allowed extensions: [‘_neutron_event.dat’, ‘_neutron0_event.dat’, ‘_neutron1_event.dat’, ‘_neutron2_event.dat’, ‘_neutron3_event.dat’, ‘_neutron4_event.dat’, ‘_live_neutron_event.dat’]

PulseidFilename

Input

string

File containing the accelerator pulse information; the filename will be found automatically if not specified. Allowed extensions: [‘_pulseid.dat’, ‘_pulseid0.dat’, ‘_pulseid1.dat’, ‘_pulseid2.dat’, ‘_pulseid3.dat’, ‘_pulseid4.dat’, ‘_live_pulseid.dat’]

MappingFilename

Input

string

File containing the pixel mapping (DAS pixels to pixel IDs) file (typically INSTRUMENT_TS_YYYY_MM_DD.dat). The filename will be found automatically if not specified. Allowed extensions: [‘.dat’]

SpectrumList

Input

long list

A list of individual spectra (pixel IDs) to read, specified as e.g. 10:20. Only used if set.

ChunkNumber

Input

number

Optional

If loading the file by sections (‘chunks’), this is the section number of this execution of the algorithm.

TotalChunks

Input

number

Optional

If loading the file by sections (‘chunks’), this is the total number of sections.

UseParallelProcessing

Input

string

Auto

Use multiple cores for loading the data? Auto: Use serial loading for small data sets, parallel for large data sets. Serial: Use a single core. Parallel: Use all available cores. Allowed values: [‘Auto’, ‘Serial’, ‘Parallel’]

OutputWorkspace

Output

IEventWorkspace

Mandatory

The name of the workspace that will be created, filled with the read-in data and stored in the [[Analysis Data Service]].

EventNumberWorkspace

Output

MatrixWorkspace

Workspace with number of events per pulse

DBOutputBlockNumber

Input

number

Optional

DBNumberOutputEvents

Input

number

40

Number of output events for debugging purpose. Must be defined with DBOutputBlockNumber.

DBNumberOutputPulses

Input

number

Optional

Number of output pulses for debugging purpose.

## Description¶

The LoadEventPreNeXus algorithm stores data from the pre-nexus neutron event data file in an EventWorkspace. The default histogram bin boundaries consist of a single bin able to hold all events (in all pixels), and will have their units set to time-of-flight. Since it is an EventWorkspace, it can be rebinned to finer bins with no loss of data.

### Optional properties¶

Specific pulse ID and mapping files can be specified if needed; these are guessed at automatically from the neutron filename, if not specified.

A specific list of pixel ids can be specified, in which case only events relating to these pixels will appear in the output.

The ChunkNumber and TotalChunks properties can be used to load only a section of the file; e.g. if these are 1 and 10 respectively only the first 10% of the events will be loaded.

Categories: AlgorithmIndex | DataHandling\PreNexus