3.3.44. NXsource

Status:

base class, extends NXobject, version 1.0

Description:

Template of the neutron or x-ray source, insertion devices and/or moderators.

Symbols:

No symbol table

Groups cited:

NXdata, NXgeometry, NXnote

Structure:

distance: NX_FLOAT {units=NX_LENGTH}

Effective distance from sample Distance as seen by radiation from sample. This number should be negative to signify that it is upstream of the sample.

name: NX_CHAR

Name of source

@short_name: NX_CHAR

short name for source, perhaps the acronym

type: NX_CHAR

type of radiation source (pick one from the enumerated list and spell exactly)

Any of these values:

• Spallation Neutron Source
• Pulsed Reactor Neutron Source
• Reactor Neutron Source
• Synchrotron X-ray Source
• Pulsed Muon Source
• Rotating Anode X-ray
• Fixed Tube X-ray
• UV Laser
• Free-Electron Laser
• Optical Laser
• Ion Source
• UV Plasma Source

probe: NX_CHAR

type of radiation probe (pick one from the enumerated list and spell exactly)

Any of these values:

• neutron
• x-ray
• muon
• electron
• ultraviolet
• visible light
• positron
• proton

power: NX_FLOAT {units=NX_POWER}

Source power

emittance_x: NX_FLOAT {units=NX_EMITTANCE}

Source emittance (nm-rad) in X (horizontal) direction.

emittance_y: NX_FLOAT {units=NX_EMITTANCE}

Source emittance (nm-rad) in Y (horizontal) direction.

sigma_x: NX_FLOAT {units=NX_LENGTH}

particle beam size in x

sigma_y: NX_FLOAT {units=NX_LENGTH}

particle beam size in y

flux: NX_FLOAT {units=NX_FLUX}

Source intensity/area (example: s-1 cm-2)

energy: NX_FLOAT {units=NX_ENERGY}

Source energy. For storage rings, this would be the particle beam energy. For X-ray tubes, this would be the excitation voltage.

current: NX_FLOAT {units=NX_CURRENT}

Accelerator, X-ray tube, or storage ring current

voltage: NX_FLOAT {units=NX_VOLTAGE}

Accelerator voltage

frequency: NX_FLOAT {units=NX_FREQUENCY}

Frequency of pulsed source

period: NX_FLOAT {units=NX_PERIOD}

Period of pulsed source

target_material: NX_CHAR

Pulsed source target material

Any of these values:

• Ta
• W
• depleted_U
• enriched_U
• Hg
• Pb
• C

number_of_bunches: NX_INT

For storage rings, the number of bunches in use.

bunch_length: NX_FLOAT {units=NX_TIME}

For storage rings, temporal length of the bunch

bunch_distance: NX_FLOAT {units=NX_TIME}

For storage rings, time between bunches

pulse_width: NX_FLOAT {units=NX_TIME}

temporal width of source pulse

mode: NX_CHAR

source operating mode

Any of these values:

• Single Bunch: for storage rings
• Multi Bunch: for storage rings

top_up: NX_BOOLEAN

Is the synchrotron operating in top_up mode?

last_fill: NX_NUMBER {units=NX_CURRENT}

For storage rings, the current at the end of the most recent injection.

@time: NX_DATE_TIME

date and time of the most recent injection.

notes: NXnote

any source/facility related messages/events that occurred during the experiment

bunch_pattern: NXdata

For storage rings, description of the bunch pattern. This is useful to describe irregular bunch patterns.

title: NX_CHAR

name of the bunch pattern

pulse_shape: NXdata

source pulse shape

geometry: NXgeometry

“Engineering” location of source

distribution: NXdata

The wavelength or energy distribution of the source

Source:

Automatically generated from https://github.com/nexusformat/definitions/blob/master/base_classes/NXsource.nxdl.xml