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IndirectTransmission v1

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Summary

Calculates the scattering & transmission for Indirect Geometry spectrometers.

Properties

Name

Direction

Type

Default

Description

Instrument

Input

string

IRIS

Instrument. Allowed values: [‘IRIS’, ‘OSIRIS’, ‘TOSCA’, ‘BASIS’, ‘VISION’, ‘IN16B’]

Analyser

Input

string

graphite

Analyser. Allowed values: [‘graphite’, ‘mica’, ‘fmica’, ‘silicon’]

Reflection

Input

string

2

Reflection. Allowed values: [‘002’, ‘004’, ‘006’, ‘111’, ‘311’]

ChemicalFormula

Input

string

Mandatory

Sample chemical formula

DensityType

Input

string

Mass Density

Use of Mass density or Number density. Allowed values: [‘Mass Density’, ‘Number Density’]

Density

Input

number

0.1

Mass density (g/cm^3) or Number density (atoms/Angstrom^3). Default=0.1

Thickness

Input

number

0.1

Sample thickness (cm). Default=0.1

OutputWorkspace

Output

Workspace

Mandatory

The name of the output workspace.

Description

Calculates the scattering & transmission for Indirect Geometry spectrometers at the elastic peak, as the transmission variation over wavelength is not substantial.

The sample chemical formula is input for the SetSampleMaterial algorithm to calculate the cross-sections. The instrument analyser reflection is selected to obtain the wavelength of the elastic peak to calculate the absorption cross-section. The sample mass density/number density & thickness is input to then calculate the percentage scattering & transmission.

Usage

Example - Running IndirectTransmission.

table_ws = IndirectTransmission(Instrument='IRIS', ChemicalFormula="C")
param_names = table_ws.column(0)
param_values = table_ws.column(1)

for pair in zip(param_names, param_values):
  print("{} : {:1.10f}".format(pair[0], pair[1]))

Output:

Wavelength : 6.6580023372
Absorption Xsection : 0.0129590747
Coherent Xsection : 5.5510000000
Incoherent Xsection : 0.0010000000
Total scattering Xsection : 5.5520000000
Number density : 0.0050139807
Thickness : 0.1000000000
Transmission (abs+scatt) : 0.9972136294
Total scattering : 0.0027798910

Example - Running IndirectTransmission with a specified number density and thickness.

table_ws = IndirectTransmission(Instrument='OSIRIS', DensityType='Number Density', Density=0.5, Thickness=0.3, ChemicalFormula="C")
param_names = table_ws.column(0)
param_values = table_ws.column(1)

for pair in zip(param_names, param_values):
  print("{} : {:1.10f}".format(pair[0], pair[1]))

Output:

Wavelength : 6.6580023372
Absorption Xsection : 0.0129590747
Coherent Xsection : 5.5510000000
Incoherent Xsection : 0.0010000000
Total scattering Xsection : 5.5520000000
Number density : 0.5000000000
Thickness : 0.3000000000
Transmission (abs+scatt) : 0.4339856278
Total scattering : 0.5651699440

Categories: AlgorithmIndex | Workflow\MIDAS

Source

Python: IndirectTransmission.py