Add Vanadium (V-Nb) consideration into EnginX algorithms

[lottiegreenwood]

This issue was originally TRAC 11588

This ticket is blocks : TRAC8368

Currently EnginX CalibrateAll does not consider the vanadium number when calibrating. This is necessary to get useful calibration results.

In order to do this, there are two methods:

'''Method one'''

1. Add in option to load the ceria and vanadium numbers

2. Fit a spline to each pixel (V-Nb) and store them with vanadium in a filename

3. Divide each Ceria pixel by the spline

'''Method two'''

1. Add in option to load the ceria and vanadium numbers

2. Add together each V-Nb pixel to get 1 number (the sensitivity) and store it

3. Divide the ceria pixel with corrected sensitivity number

4. Convert unit to dspacing on V-Nb and add each bank together to get 2 spectr.

5. Fit spline to 2 spectrum and store

6. Convert unit ceria to dspacing and divide each pixel with the corresponding curve

7. Divide each ceria pixel by corrected sensitivity number

[lottiegreenwood]

@lottiegreenwood (2015-04-20T08:14:36):
After testing, method 1 is found to be too noisy and not produce accurate results. So method 2 will be followed

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@lottiegreenwood (2015-04-21T08:12:42):
From further discussion with EnginX Scientists, the scope of this ticket is expanded somewhat.

• CalibrateFull needs to include loading and preparing vanadium for fitting, along with a calibration

• Calibrate needs to do as above but save the two splines and sensitivities outputted from the vanadium calibration

• EnginXFocus should be renamed as EnginXDetFocus and a new EnginXFocus should be created that takes Difc and Zero from EnginXCalibrate rather than Detector Positions

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@NickDraper (2015-04-27T08:10:35):
Moved to R3.5 at the R3.4 code freeze

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Federico M Pouzols (2015-05-06T15:52:18):
(In http://trac.mantidproject.org/mantid/ticket/8368) Added new ENGIN-X tickets that have been opened in the last few months as 'blocked by'.

[FedeMPouzols]

From further discussions:

• Method 1 is not a good option. Go for method 2.
• This vanadium consideration or correction needs to be added into EnginXFocus and EnginXCalibrateFull. Both algorithm will need an additional, mandatory input, say VanadiumFile.
• Steps for the Vanadium correction:
  • sensitivity correction.
  • pixel-by-pixel (detector-by-detector) correction.

To do the sensitivity correction:

• In ToF space, for every spectrum, every bin of the input data needs to be rescaled by multiplying by the following value from the vanadium data: bin * (integral of spectrum) / (number_of_bins). when this is done, remember to double-check with scientists that with this we get a proper normalization or scale.

To do the pixel-by-pixel correction:

• All in d-spacing. Take all the spectra of one bank and sum them all. Fit a spline to the sum. For every spectrum, divide by it. Do this for bank 1 and bank 2 separately.