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LRScalingFactors v1¶

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Summary ¶

Liquids Reflectometer (REFL) scaling factor calculation

Properties ¶

Name	Direction	Type	Default	Description
DirectBeamRuns	Input	long list		Run number of the signal run to use
Attenuators	Input	long list		Number of attenuators for each run
TOFRange	Input	dbl list	10000,35000	TOF range to use
SignalPeakPixelRange	Input	long list	150,160	Pixel range defining the data peak
SignalBackgroundPixelRange	Input	long list	147,163	Pixel range defining the background
LowResolutionPixelRange	Input	long list	2147483647,2147483647	Pixel range defining the region to use in the low-resolution direction
IncidentMedium	Input	string	Medium	Name of the incident medium
FrontSlitName	Input	string	S1	Name of the front slit
BackSlitName	Input	string	Si	Name of the back slit
TOFSteps	Input	number	500	TOF step size
SlitTolerance	Input	number	0.02	Tolerance for matching slit positions
ScalingFactorFile	Input	string	Mandatory	Allowed values: [‘cfg’]

Description ¶

Used in the Liquids Reflectometer reduction at the SNS, this algorithm computes the absolute scaling factors for the data sets that we are going to stitch together.

The algorithm runs through a sequence of direct beam data sets to extract scaling factors. The method was developed by J. Ankner (ORNL).

As we loop through, we find matching data sets with the only difference between the two is an attenuator. The ratio of those matching data sets allows use to rescale a direct beam run taken with a larger number of attenuators to a standard data set taken with tighter slit settings and no attenuators.

The normalization run for a data set taken in a given slit setting configuration can then be expressed in terms of the standard 0-attenuator data set with: \(D_i = F_i D_0\)

Here’s an example of runs and how they are related to F.