SANSCalculateTransmission v1

../_images/SANSCalculateTransmission-v1_dlg.png

SANSCalculateTransmission dialog.

Summary

Calculates the transmission for a SANS reduction.

Properties

Name Direction Type Default Description
SANSState Input Dictionary   A property manager which fulfills the SANSState contract.
TransmissionWorkspace Input MatrixWorkspace Mandatory The transmission workspace in time-of-flight units.
DirectWorkspace Input MatrixWorkspace Mandatory The direct workspace in time-of-flight units.
DataType Input string Sample The component of the instrument which is to be reduced. Allowed values: [‘Sample’, ‘Can’]
OutputWorkspace Output MatrixWorkspace Mandatory A calculated transmission workspace in units of wavelength.
UnfittedData Output MatrixWorkspace Mandatory An unfitted data in units of wavelength.

Description

This algorithm provides a transmission workspace for subsequent wavelength correction in Q1D v2 or Qxy v1. The settings of the algorithm are provided by the state object. The user provides a TransmissionWorkspace, DirectWorkspace and the data type which is to be used, ie Sample or Can. The OutputWorkspace is a fitted workspace, but the unfitted data set is available via UnfittedData.

Currently the mask mechanism is implemented for SANS2D, LOQ and LARMOR.

Relevant SANSState entries for SANSCalculateTransmission

The required information for the transmission calculation is retrieved from a state object.

The elements are:

Entry Type Description Mandatory Default
transmission_radius_on_detector Float A radius on the detector No None
transmission_roi_files List of String A list of ROI file names No None
transmission_mask_files List of String A list of mask file names No None
default_transmission_monitor Integer The default transmission monitor auto setup auto
transmission_monitor Integer The transmission monitor No None
default_incident_monitor Integer The default incident monitor auto setup auto
incident_monitor Integer The incident monitor No None
prompt_peak_correction_min Float Min time of the prompt peak No None
prompt_peak_correction_max Float Max time of the prompt peak No None
prompt_peak_correction_enabled Bool If using prompt peak correction No False
use_full_wavelength_range Bool If using full wavelength range No False
wavelength_full_range_low Float Min of instrument’s full wav. range auto setup auto
wavelength_full_range_high Float Max of instrument’s full wav. range auto setup auto
background_TOF_general_start Float General background corr. start time No None
background_TOF_general_stop Float General background corr. stop time No None
background_TOF_monitor_start Dict Monitor num vs background corr. start time No None
background_TOF_monitor_stop Dict Monitor num vs background corr. stop time No None
background_TOF_roi_start Float ROI background corr. start time No None
background_TOF_roi_stop Float ROI background corr. stop time No None
fit Dict DataType enum (Sample and Can) vs fit state No None

There is a fit state for the sample and the can which contains the following settings:

Entry Type Description Mandatory Default
fit_type FitType enum The type of fit, ie log, lin, poly. No log
polynomial_order Integer The polynomial order when using polynomial fitting No 0
wavelength_low Float Lower wavelength bound No None
wavelength_high Float Upper wavelength bound No None

Note that the prompt peak settings are automatically set up for LOQ

Note that these settings should be only populated via the GUI or the Python Interface of ISIS SANS.

Categories: Algorithm Index | SANS\Adjust

Source

Python: SANSCalculateTransmission.py (last modified: 2018-10-05)