NXtransmission

Status:

application definition, extends NXobject

Description:

Application definition for transmission experiments

Symbols:

Variables used throughout the experiment

N_wavelengths: Number of wavelength points

N_scans: Number of scans

Groups cited:

NXattenuator, NXdata, NXdetector, NXentry, NXfabrication, NXgrating, NXinstrument, NXmonochromator, NXsample, NXslit, NXsource, NXuser

Structure:

ENTRY: (required) NXentry

This application definition

definition: (required) NX_CHAR

An application definition for transmission.

Obligatory value: NXtransmission

@version: (required) NX_CHAR

Version number to identify which definition of this application definition was used for this entry/data.

@url: (required) NX_CHAR

URL where to find further material (documentation, examples) relevant to the application definition.

start_time: (required) NX_DATE_TIME

Start time of the experiment.

experiment_identifier: (required) NX_CHAR

Unique identifier of the experiment, such as a (globally persistent)

unique identifier.

  • The identifier is usually defined by the facility or principle investigator.

  • The identifier enables to link experiments to e.g. proposals.

experiment_description: (optional) NX_CHAR

An optional free-text description of the experiment. However, details of the experiment should be defined in the specific fields of this application definition rather than in this experiment description.

acquisition_program: (optional) NXfabrication

@url: (recommended) NX_CHAR

Website of the software

model: (required) NX_CHAR

Commercial or otherwise defined given name to the program that was used to generate the result file(s) with measured data and metadata.

identifier: (required) NX_CHAR

Version number of the program that was used to generate the result file(s) with measured data and metadata.

operator: (required) NXuser

Contact information of at least the user of the instrument or the investigator who performed this experiment. Adding multiple users if relevant is recommended.

name: (required) NX_CHAR

Name of the user.

affiliation: (required) NX_CHAR

Name of the affiliation of the user at the point in time when the experiment was performed.

address: (required) NX_CHAR

Street address of the user’s affiliation.

email: (required) NX_CHAR

Email address of the user.

url: (recommended) NX_CHAR

Author ID defined by reasearch id services, e.g. orcid (https://orcid.org/).

telephone_number: (recommended) NX_CHAR

Telephone number of the user.

instrument: (required) NXinstrument

common_beam_depolarizer: (required) NX_BOOLEAN

If true, the incident beam is depolarized.

polarizer: (required) NX_NUMBER {units=NX_ANGLE}

Polarizer value inside the beam path

time_points: (optional) NX_NUMBER (Rank: 1, Dimensions: [N_scans]) {units=NX_TIME}

An array of relative scan start time points.

measured_data: (required) NX_NUMBER (Rank: 2, Dimensions: [N_scans, N_wavelengths])

Resulting data from the measurement. The length of the 2nd dimension is the number of time points. If it has length one the time_points may be empty.

manufacturer: (recommended) NXfabrication

Manufacturer of the instrument.

common_beam_mask: (required) NXslit

Common beam mask to shape the incident beam

y_gap: (required) NX_NUMBER {units=NX_UNITLESS}

The height of the common beam in percentage of the beam

ref_attenuator: (required) NXattenuator

Attenuator in the reference beam

attenuator_transmission: (required) NX_FLOAT

sample_attenuator: (required) NXattenuator

Attenuator in the sample beam

attenuator_transmission: (required) NX_FLOAT

spectrometer: (required) NXmonochromator

wavelength: (required) NX_NUMBER (Rank: 1, Dimensions: [N_wavelengths]) {units=NX_LENGTH}

Wavelength value(s) used for the measurement. An array of 1 or more elements. Length defines N_wavelenghts

spectral_resolution: (optional) NX_NUMBER {units=NX_WAVENUMBER}

Overall spectral resolution of this spectrometer. If several gratings are employed the spectral resoultion should rather be specified for each grating inside the NXgrating group of this spectrometer.

GRATING: (optional) NXgrating

Diffraction grating, as could be used in a monochromator. If two or more gratings were used, define the angular dispersion and the wavelength range (min/max wavelength) for each grating and make sure that the wavelength ranges do not overlap. The dispersion should be defined for the entire wavelength range of the experiment.

angular_dispersion: (optional) NX_NUMBER

Dispersion of the grating in nm/mm used.

blaze_wavelength: (optional) NX_NUMBER {units=NX_LENGTH}

The blaze wavelength of the grating used.

spectral_resolution: (optional) NX_NUMBER {units=NX_WAVENUMBER}

Overall spectral resolution of the instrument when this grating is used.

wavelength_range: (required) NX_NUMBER (Rank: 1, Dimensions: [2]) {units=NX_LENGTH}

Wavelength range in which this grating was used

DETECTOR: (required) NXdetector

wavelength_range: (required) NX_NUMBER (Rank: 1, Dimensions: [2]) {units=NX_LENGTH}

Wavelength range in which this detector was used

type: (required) NX_CHAR

Detector type

Any of these values: PMT | PbS | InGaAs

response_time: (optional) NX_NUMBER {units=NX_TIME}

Response time of the detector

gain: (optional) NX_NUMBER

Detector gain

slit: (required) NXslit

Slit setting used for measurement with this detector

type: (required) NX_CHAR

Any of these values: fixed | servo

SOURCE: (required) NXsource

The lamp used for illumination

type: (required) NX_CHAR

The type of lamp, e.g. halogen, D2 etc.

Any of these values: halogen | D2

spectrum: (optional) NX_NUMBER (Rank: 1, Dimensions: [N_wavelengths])

The spectrum of the lamp used

wavelength_range: (required) NX_NUMBER (Rank: 1, Dimensions: [2]) {units=NX_LENGTH}

Wavelength range in which the lamp was used

SAMPLE: (required) NXsample

Properties of the sample measured

name: (required) NX_CHAR

data: (required) NXdata

A default view of the data emitted intensity vs. wavelength. From measured_data plot intensity and wavelength.

@axes: (required) NX_CHAR

We recommend to use wavelength as a default attribute, but it can be replaced by any suitable parameter along the X-axis.

Hypertext Anchors

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

NXDL Source:

https://github.com/FAIRmat-Experimental/nexus_definitions/tree/fairmat/contributed_definitions/NXtransmission.nxdl.xml