DetectorEfficiencyCorUser v1¶

DetectorEfficiencyCorUser dialog.

Table of Contents

Summary
Properties
Description
Usage
Source

Summary ¶

This algorithm calculates the detector efficiency according the formula set in the instrument definition file/parameters.

Properties ¶

Name	Direction	Type	Default	Description
InputWorkspace	Input	MatrixWorkspace	Mandatory	The workspace to correct for detector efficiency
OutputWorkspace	Output	MatrixWorkspace	Mandatory	The name of the workspace in which to store the result.
IncidentEnergy	Input	number	Optional	The energy of neutrons leaving the source.

Description ¶

This algorithm will correct detector efficiency according to the ILL INX program for time-of-flight data reduction.

A formula named “formula_eff” must be defined in the instrument parameters file. The input workspace must be in DeltaE units.

The output data will be corrected as:

$y = \frac{y}{eff}$

where $eff$ is

$eff = \frac{f(Ei - \Delta E)}{f(E_i)}$

The function $f$ is defined as “formula_eff” in the IDF. To date this has been implemented at the ILL for ILL IN4, IN5 and IN6.

Usage ¶

Example - A sample correction

# a sample workspace with a sample instrument
ws = CreateSampleWorkspace()
# convert to Wavelength
ws = ConvertUnits(ws,"DeltaE",EMode="Direct",EFixed=3.27)

correction_formula = "exp(-0.0565/sqrt(e))*(1.0-exp(-3.284/sqrt(e)))"
SetInstrumentParameter(ws,ParameterName="formula_eff",Value=correction_formula)


#Now we are ready to run the correction
wsCorrected = DetectorEfficiencyCorUser(ws)


print ("The correction correct the data by the user defined function.")
print ("In this case: " + correction_formula)
for i in range(0,wsCorrected.blocksize(),10):
  print ("The correct value in bin %i is %.2f compared to %.2f" % (i,wsCorrected.readY(0)[i],ws.readY(0)[i]))

Output:

The correction correct the data by the user defined function.
In this case: exp(-0.0565/sqrt(e))*(1.0-exp(-3.284/sqrt(e)))
The correct value in bin 0 is 5.53 compared to 0.30
The correct value in bin 10 is 0.53 compared to 0.30
The correct value in bin 20 is 0.36 compared to 0.30
The correct value in bin 30 is 0.30 compared to 0.30

Categories: Algorithms | CorrectionFunctions | EfficiencyCorrections | Inelastic