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IndirectTransmission v1¶

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