From 1baa6893b090ace8306f9a608b4b52d1b865244d Mon Sep 17 00:00:00 2001
From: Joseph Ramsay <joseph.ramsay@stfc.ac.uk>
Date: Thu, 10 Aug 2017 16:06:11 +0100
Subject: [PATCH] Re #20219 Use MayersSC for non-vanadium samples
---
.../routines/absorb_corrections.py | 44 +++++++------------
.../Diffraction/isis_powder/routines/focus.py | 8 ++--
2 files changed, 20 insertions(+), 32 deletions(-)
diff --git a/scripts/Diffraction/isis_powder/routines/absorb_corrections.py b/scripts/Diffraction/isis_powder/routines/absorb_corrections.py
index 811196ed4e7..84d73e2ac09 100644
--- a/scripts/Diffraction/isis_powder/routines/absorb_corrections.py
+++ b/scripts/Diffraction/isis_powder/routines/absorb_corrections.py
@@ -78,7 +78,7 @@ def _calculate__cylinder_absorb_corrections(ws_to_correct, multiple_scattering,
sample_details_obj=sample_details_obj)
ws_to_correct = _do_cylinder_absorb_corrections(ws_to_correct=ws_to_correct,
multiple_scattering=multiple_scattering,
- is_vanadium=is_vanadium, sample_details=sample_details_obj)
+ is_vanadium=is_vanadium)
return ws_to_correct
@@ -99,36 +99,24 @@ def _setup_sample_for_cylinder_absorb_corrections(ws_to_correct, sample_details_
mantid.SetSample(InputWorkspace=ws_to_correct, Geometry=geometry_json, Material=material_json)
-def _do_cylinder_absorb_corrections(ws_to_correct, multiple_scattering, is_vanadium, sample_details):
+def _do_cylinder_absorb_corrections(ws_to_correct, multiple_scattering, is_vanadium):
previous_units = ws_to_correct.getAxis(0).getUnit().unitID()
ws_units = common_enums.WORKSPACE_UNITS
+ # Mayers Sample correction must be completed in TOF, convert if needed. Then back to original units afterwards
+ if previous_units != ws_units.tof:
+ ws_to_correct = mantid.ConvertUnits(InputWorkspace=ws_to_correct, Target=ws_units.tof)
+
if is_vanadium:
- # Mayers Sample correction must be completed in TOF, convert if needed. Then back to original units afterwards
- if previous_units != ws_units.tof:
- ws_to_correct = mantid.ConvertUnits(InputWorkspace=ws_to_correct, Target=ws_units.tof)
ws_to_correct = mantid.MayersSampleCorrection(InputWorkspace=ws_to_correct,
MultipleScattering=multiple_scattering)
- if previous_units != ws_units.tof:
- ws_to_correct = mantid.ConvertUnits(InputWorkspace=ws_to_correct, Target=previous_units)
- return ws_to_correct
-
- else: # Sample is not vanadium
- # Cylinder Absorption correction must be in units of wavelength, convert if needed, then back afterwards
- if previous_units != ws_units.wavelength:
- ws_to_correct = mantid.ConvertUnits(InputWorkspace=ws_to_correct, Target=ws_units.wavelength,
- OutputWorkspace=ws_to_correct)
-
- attenuation_factors_ws = mantid.CloneWorkspace(InputWorkspace=ws_to_correct)
- attenuation_factors_ws = mantid.CylinderAbsorption(InputWorkspace=attenuation_factors_ws,
- CylinderSampleHeight=sample_details.height,
- CylinderSampleRadius=sample_details.radius)
- ws_to_correct = mantid.Divide(LHSWorkspace=ws_to_correct, RHSWorkspace=attenuation_factors_ws,
- OutputWorkspace=ws_to_correct)
- common.remove_intermediate_workspace(attenuation_factors_ws)
-
- if previous_units != ws_units.wavelength:
- ws_to_correct = mantid.ConvertUnits(InputWorkspace=ws_to_correct, Target=previous_units,
- OutputWorkspace=ws_to_correct)
-
- return ws_to_correct
+ else:
+ # Ensure we never do multiple scattering if the sample is not isotropic (e.g. not a Vanadium)
+ ws_to_correct = mantid.MayersSampleCorrection(InputWorkspace=ws_to_correct,
+ MultipleScattering=False)
+ if previous_units != ws_units.tof:
+ ws_to_correct = mantid.ConvertUnits(InputWorkspace=ws_to_correct, Target=previous_units)
+ return ws_to_correct
+
+
+
diff --git a/scripts/Diffraction/isis_powder/routines/focus.py b/scripts/Diffraction/isis_powder/routines/focus.py
index a9ed960326c..c131aff4e1d 100644
--- a/scripts/Diffraction/isis_powder/routines/focus.py
+++ b/scripts/Diffraction/isis_powder/routines/focus.py
@@ -36,14 +36,14 @@ def _focus_one_ws(ws, run_number, instrument, perform_vanadium_norm, absorb):
# Crop to largest acceptable TOF range
input_workspace = instrument._crop_raw_to_expected_tof_range(ws_to_crop=input_workspace)
+ # Correct for absorption / multiple scattering if required
+ if absorb:
+ input_workspace = instrument._apply_absorb_corrections(run_details=run_details, ws_to_correct=input_workspace)
+
# Align
aligned_ws = mantid.AlignDetectors(InputWorkspace=input_workspace,
CalibrationFile=run_details.offset_file_path)
- # Correct for absorption / multiple scattering if required
- if absorb:
- aligned_ws = instrument._apply_absorb_corrections(run_details=run_details, ws_to_correct=aligned_ws)
-
# Focus the spectra into banks
focused_ws = mantid.DiffractionFocussing(InputWorkspace=aligned_ws,
GroupingFileName=run_details.grouping_file_path)
--
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