NXsource¶
Status:
base class, extends NXobject
Description:
The neutron or x-ray storage ring/facility.
Symbols:
The symbols used in the schema to specify e.g. dimensions of arrays
nx: Number of points in a spectrum
- Groups cited:
Structure:
@default: (optional) NX_CHAR
Declares which child group contains a path leading to a NXdata group.
It is recommended (as of NIAC2014) to use this attribute to help define the path to the default dataset to be plotted. See https://www.nexusformat.org/2014_How_to_find_default_data.html for a summary of the discussion.
distance: (optional) 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: (optional) NX_CHAR
type: (optional) 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
Metal Jet X-ray
arc lamp
halogen lamp
LED
probe: (optional) 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: (optional) NX_FLOAT {units=NX_POWER}
Source power
emittance_x: (optional) NX_FLOAT {units=NX_EMITTANCE}
Source emittance (nm-rad) in X (horizontal) direction.
emittance_y: (optional) NX_FLOAT {units=NX_EMITTANCE}
Source emittance (nm-rad) in Y (horizontal) direction.
sigma_x: (optional) NX_FLOAT {units=NX_LENGTH}
Particle beam size in x
sigma_y: (optional) NX_FLOAT {units=NX_LENGTH}
Particle beam size in y
flux: (optional) NX_FLOAT {units=NX_FLUX}
Source intensity/area (example: s-1 cm-2)
energy: (optional) 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: (optional) NX_FLOAT {units=NX_CURRENT}
Accelerator, X-ray tube, or storage ring current
voltage: (optional) NX_FLOAT {units=NX_VOLTAGE}
Accelerator voltage
frequency: (optional) NX_FLOAT {units=NX_FREQUENCY}
Frequency of pulsed source
period: (optional) NX_FLOAT {units=NX_PERIOD}
Period of pulsed source
target_material: (optional) NX_CHAR
Pulsed source target material or other material used to generate light, e.g. He, Ar gas for lasers, Xe or Hg/Cd vapor for arc lamps, etc.
Any of these values:
Ta
W
depleted_U
enriched_U
Hg
Pb
C
Ar
He
Xe
Hg/Cd
H
number_of_bunches: (optional) NX_INT
For storage rings, the number of bunches in use.
bunch_length: (optional) NX_FLOAT {units=NX_TIME}
For storage rings, temporal length of the bunch
bunch_distance: (optional) NX_FLOAT {units=NX_TIME}
For storage rings, time between bunches
pulse_width: (optional) NX_FLOAT {units=NX_TIME}
Temporal width of source pulse
mode: (optional) NX_CHAR
Source operating mode
Any of these values:
Single Bunch
: For storage rings
Multi Bunch
: For storage ringstop_up: (optional) NX_BOOLEAN
Is the synchrotron operating in top_up mode?
last_fill: (optional) NX_NUMBER {units=NX_CURRENT}
For storage rings, the current at the end of the most recent injection.
@time: (optional) NX_CHAR
Date and time of the most recent injection.
photon_energy: (optional) NX_FLOAT {units=NX_ENERGY}
The center photon energy of the source, before it is monochromatized or converted
center_wavelength: (optional) NX_FLOAT {units=NX_WAVELENGTH}
The center wavelength of the source, before it is monochromatized or converted
pulse_energy: (optional) NX_FLOAT {units=NX_ENERGY}
For pulsed sources, the energy of a single pulse
peak_power: (optional) NX_FLOAT {units=NX_POWER}
For pulsed sources, the pulse energy divided by the pulse duration
bunch_number_start: (optional) NX_INT
Some facilities tag each bunch. First bunch of the measurement
bunch_number_end: (optional) NX_INT
Last bunch of the measurement
notes: (optional) NXnote
Any source/facility related messages/events that occurred during the experiment
bunch_pattern: (optional) NXdata
For storage rings, description of the bunch pattern. This is useful to describe irregular bunch patterns.
title: (optional) NX_CHAR
name of the bunch pattern
pulse_shape: (optional) NXdata
Source pulse shape
geometry: (optional) NXgeometry
‘Engineering’ location of source
distribution: (optional) NXdata
The wavelength or energy distribution of the source
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.