Refs #9643. Added doc file.

Code/Mantid/docs/source/algorithms/LoadVulcanCalFile-v1.rst

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+.. algorithm::
+
+.. summary::
+
+.. alias::
+
+.. properties::
+
+Description
+-----------
+
+This algorithm loads a set of VULCAN's calibration files, including
+detector offset file and bad pixel file, and convert VULCAN's offset
+on time-of-flight to Mantid's offset on d-spacing.
+
+By this algorithm, Vulcan's calibration file can be converted to
+the standard calibration file for SNSPowderReduction.
+
+Detector offset file
+====================
+
+There are :math:`62500` (:math:`50\times 1250`) rows in the offset file.
+In each row, the first value is the pixel ID; and the second is inner-module offset.
+
+For each module, it starts from row :math:`1250\times M_{i}`, where :math:`M_{i}` is the module ID starting
+from 0.
+
+- Line :math:`1250\times M_i + 0`: pixel ID, offset (first detector in module)
+- Line :math:`1250\times M_i + 1`: pixel ID, offset
+- ... ...
+- Line :math:`1250\times M_i + 1231`: pixle ID, offset (last detector in module)
+- Line :math:`1250\times M_i + 1232`: pixel ID, offset (detector is not used)
+- ... ...
+- Line :math:`1250\times M_i + 1248`: pixel ID, inter module correction
+- Line :math:`1250\times M_i + 1249`: pixel ID, inter bank correction
+
+Bad pixel file
+==============
+
+In bad pixel file, each line contains one and only one integer
+corresponding to the detector ID of a bad pixel.
+The bad pixels will be masked in the output MaskWorkspace.
+
+Conversion from offset in TOF to d-spacing
+==========================================
+
+With VULCAN's offsets in TOF, the calibration is done as the following.
+
+ :math:`\log_{10}(\xi) = \log_{10}(\xi_0) + \log_{10}(\xi_1) + \log_{10}(\xi_2)`
+
+ :math:`\log_{10}(T')  = \log_{10}(T) - \log_{10}(\xi)`
+
+ :math:`T' = \frac{T}{\xi}`
+
+where (1) :math:`\xi_0` is the inner-bank correction, (2) :math:`\xi_1` is the inner module (inter-bank) correction,
+and (3) :math:`\xi_2` is the inter-module (inner-pack) correction.
+
+Be noticed that the correction factor recorded in VULCAN's offset file is :math:`\log(\xi)`.
+Thus if we define :math:`\Xi = \log(\xi)`, then time focussing formula used by VUCLAN's IDL code
+is :math:`T^{(f)} = \frac{T}{10^{\Xi}}`
+
+Therefore, by defining :math:`\xi^{(v)}` as the VULCAN's offset, and :math:`\xi^{(m)}` as
+the Mantid's offset, then we can convert VULCAN's offset to Mantid's as
+ :math:`\xi^{(m)} = \frac{L\cdot\sin\theta}{L'\cdot\sin\theta'}\cdot\frac{1}{\xi^{(m)}} - 1`
+
+VULCAN uses effective DIFC and :math:`2\theta` for the effective detector to be focussed on.
+It follows the Bragg rule for time-of-flight, i.e.,
+ :math:`T = DIFC \cdot d = (252.777\cdot L\cdot 2\cdot\sin\theta)\cdot d`
+
+
+Usage
+-----
+
+.. testcode:: LoadVulcanCalFile
+
+  # Load Vulcan calibration files
+  LoadVulcanCalFile(OffsetFilename='pid_offset_vulcan_new.dat',
+    BadPixelFilename='bad_pids_vulcan_new_6867_7323.dat',
+    WorkspaceName='Vulcan_idl', BankIDs='21,22,23,26,27,28',
+    EffectiveDIFCs='16372.6,16377,16372.1,16336.6,16340.8,16338.8',
+    Effective2Thetas='90.091,90.122,90.089,89.837,89.867,89.852')
+
+  # Print
+  offsetws = mtd["Vulcan_idl_offsets"]
+  groupws = mtd["Vulcan_idl_group"]
+  for iws in [0, 100, 1000, 3500, 7000]:
+    print "Spectrum %-5d Offset = %.5f of Group %d" % (iws, offsetws.readY(iws)[0], groupws.readY(iws)[0])
+  maskws = mtd["Vulcan_idl_mask"]
+  print "Size of mask workspace = %d" % (maskws.getNumberHistograms())
+
+.. testcleanup::
+
+Output:
+
+.. testoutput:: LoadVulcanCalFile
+
+  Spectrum 0     Offset = -0.00047 of Group 1
+  Spectrum 100   Offset = -0.00096 of Group 1
+  Spectrum 1000  Offset = -0.00060 of Group 1
+  Spectrum 3500  Offset = -0.00036 of Group 3
+  Spectrum 7000  Offset = 0.00058 of Group 6
+  Size of mask workspace = 7392
+
+.. categories::