IndirectTransmission v1

../_images/IndirectTransmission-v1_dlg.png

IndirectTransmission dialog.

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 (last modified: 2018-10-05)