3.3.1.21. NXfilter¶
Status:
base class, extends NXobject
Description:
For band pass beam filters.
If uncertain whether to use NXfilter (band-pass filter) or NXattenuator (reduces beam intensity), then use NXattenuator.
Symbols:
No symbol table
- Groups cited:
NXdata, NXgeometry, NXlog, NXoff_geometry, NXsensor, NXtransformations
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.
description: (optional) NX_CHAR
Composition of the filter. Chemical formula can be specified separately.
This field was changed (2010-11-17) from an enumeration to a string since common usage showed a wider variety of use than a simple list. These are the items in the list at the time of the change: Beryllium | Pyrolytic Graphite | Graphite | Sapphire | Silicon | Supermirror.
status: (optional) NX_CHAR
position with respect to in or out of the beam (choice of only “in” or “out”)
Any of these values:
in: in the beam
out: out of the beamtemperature: (optional) NX_FLOAT {units=NX_TEMPERATURE}
average/nominal filter temperature
thickness: (optional) NX_FLOAT {units=NX_LENGTH}
Thickness of the filter
density: (optional) NX_NUMBER {units=NX_MASS_DENSITY}
mass density of the filter
chemical_formula: (optional) NX_CHAR
The chemical formula specified using CIF conventions. Abbreviated version of CIF standard:
Only recognized element symbols may be used.
Each element symbol is followed by a ‘count’ number. A count of ‘1’ may be omitted.
A space or parenthesis must separate each cluster of (element symbol + count).
Where a group of elements is enclosed in parentheses, the multiplier for the group must follow the closing parentheses. That is, all element and group multipliers are assumed to be printed as subscripted numbers.
Unless the elements are ordered in a manner that corresponds to their chemical structure, the order of the elements within any group or moiety depends on whether or not carbon is present.
If carbon is present, the order should be:
C, then H, then the other elements in alphabetical order of their symbol.
If carbon is not present, the elements are listed purely in alphabetic order of their symbol.
This is the Hill system used by Chemical Abstracts.
unit_cell_a: (optional) NX_FLOAT {units=NX_LENGTH}
Unit cell lattice parameter: length of side a
unit_cell_b: (optional) NX_FLOAT {units=NX_LENGTH}
Unit cell lattice parameter: length of side b
unit_cell_c: (optional) NX_FLOAT {units=NX_LENGTH}
Unit cell lattice parameter: length of side c
unit_cell_alpha: (optional) NX_FLOAT {units=NX_ANGLE}
Unit cell lattice parameter: angle alpha
unit_cell_beta: (optional) NX_FLOAT {units=NX_ANGLE}
Unit cell lattice parameter: angle beta
unit_cell_gamma: (optional) NX_FLOAT {units=NX_ANGLE}
Unit cell lattice parameter: angle gamma
unit_cell_volume: (optional) NX_FLOAT (Rank: 1, Dimensions: [n_comp]) {units=NX_VOLUME}
Unit cell
orientation_matrix: (optional) NX_FLOAT (Rank: 3, Dimensions: [n_comp, 3, 3])
Orientation matrix of single crystal filter using Busing-Levy convention: W. R. Busing and H. A. Levy (1967). Acta Cryst. 22, 457-464
m_value: (optional) NX_FLOAT {units=NX_DIMENSIONLESS}
m value of supermirror filter
substrate_material: (optional) NX_CHAR
substrate material of supermirror filter
substrate_thickness: (optional) NX_FLOAT {units=NX_LENGTH}
substrate thickness of supermirror filter
coating_material: (optional) NX_CHAR
coating material of supermirror filter
substrate_roughness: (optional) NX_FLOAT {units=NX_LENGTH}
substrate roughness (RMS) of supermirror filter
coating_roughness: (optional) NX_FLOAT (Rank: 1, Dimensions: [nsurf]) {units=NX_LENGTH}
coating roughness (RMS) of supermirror filter
depends_on: (optional) NX_CHAR
NeXus positions components by applying a set of translations and rotations to apply to the component starting from 0, 0, 0. The order of these operations is critical and forms what NeXus calls a dependency chain. The depends_on field defines the path to the top most operation of the dependency chain or the string “.” if located in the origin. Usually these operations are stored in a NXtransformations group. But NeXus allows them to be stored anywhere.
GEOMETRY: (optional) NXgeometry
DEPRECATED: Use the field depends_on and NXtransformations to filter the beamstop and NXoff_geometry to describe its shape instead
Geometry of the filter
transmission: (optional) NXdata
Wavelength transmission profile of filter
temperature_log: (optional) NXlog
Linked temperature_log for the filter
sensor_type: (optional) NXsensor
Sensor(s)used to monitor the filter temperature
OFF_GEOMETRY: (optional) NXoff_geometry
This group describes the shape of the beam line component
TRANSFORMATIONS: (optional) NXtransformations
This is the group recommended for holding the chain of translation and rotation operations necessary to position the component within the instrument. The dependency chain may however traverse similar groups in other component groups.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.