4.3.1.15. NXdetector_module

Status:

base class, extends NXobject

Description:

Geometry and logical description of a detector module. When used, child group to NXdetector.

Many detectors consist of multiple smaller modules. Sometimes it is important to know the exact position of such modules. This is the purpose of this group. It is a child group to NXdetector.

Note, the pixel size is given as values in the array fast_pixel_direction and slow_pixel_direction.

Symbols:

No symbol table

Groups cited:

none

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.

data_origin: (optional) NX_INT

A dimension-2 or dimension-3 field which gives the indices of the origin of the hyperslab of data for this module in the main area detector image in the parent NXdetector module.

The data_origin is 0-based.

The frame number dimension (np) is omitted. Thus the data_origin field for a dimension-2 dataset with indices (np, i, j) will be an array with indices (i, j), and for a dimension-3 dataset with indices (np, i, j, k) will be an array with indices (i, j, k).

The order of indices (i, j or i, j, k) is slow to fast.

data_size: (optional) NX_INT

Two or three values for the size of the module in pixels in each direction. Dimensionality and order of indices is the same as for data_origin.

module_offset: (optional) NX_NUMBER {units=NX_LENGTH}

Offset of the module in regards to the origin of the detector in an arbitrary direction.

@transformation_type: (optional) NX_CHAR

Obligatory value: translation

@vector: (optional) NX_NUMBER

Three values that define the axis for this transformation

@offset: (optional) NX_NUMBER

A fixed offset applied before the transformation (three vector components).

@offset_units: (optional) NX_CHAR

Units of the offset.

@depends_on: (optional) NX_CHAR

Points to the path of the next element in the geometry chain.

fast_pixel_direction: (optional) NX_NUMBER {units=NX_LENGTH}

Values along the direction of fastest varying pixel direction. Each value in this array is the size of a pixel in the units specified. Alternatively, if only one value is given, all pixels in this direction have the same value. The direction itself is given through the vector attribute.

@transformation_type: (optional) NX_CHAR

Obligatory value: translation

@vector: (optional) NX_NUMBER

Three values that define the axis for this transformation

@offset: (optional) NX_NUMBER

A fixed offset applied before the transformation (three vector components).

@offset_units: (optional) NX_CHAR

Units of the offset.

@depends_on: (optional) NX_CHAR

Points to the path of the next element in the geometry chain.

slow_pixel_direction: (optional) NX_NUMBER {units=NX_LENGTH}

Values along the direction of slowest varying pixel direction. Each value in this array is the size of a pixel in the units specified. Alternatively, if only one value is given, all pixels in this direction have the same value. The direction itself is given through the vector attribute.

@transformation_type: (optional) NX_CHAR

Obligatory value: translation

@vector: (optional) NX_NUMBER

Three values that define the axis for this transformation

@offset: (optional) NX_NUMBER

A fixed offset applied before the transformation (three vector components).

@offset_units: (optional) NX_CHAR

Units of the offset.

@depends_on: (optional) NX_CHAR

Points to the path of the next element in the geometry chain.

depends_on: (optional) NX_CHAR

Points to the start of the dependency chain for this module.

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/base_classes/NXdetector_module.nxdl.xml