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, NXsensor

Structure:

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 beam

temperature: (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[n_comp]: (optional) NX_FLOAT {units=NX_VOLUME}

Unit cell

orientation_matrix[n_comp, 3, 3]: (optional) NX_FLOAT

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[nsurf]: (optional) NX_FLOAT {units=NX_LENGTH}

coating roughness (RMS) of supermirror filter

(geometry): (optional) NXgeometry

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
NXDL Source:
https://github.com/nexusformat/definitions/blob/master/base_classes/NXfilter.nxdl.xml