XML Geometry, Rotations and the CAL by usr10478

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									 XML Geometry, Rotations and the CAL




16 Aug 2002         1          J. Bogart
                          CsIElement

z




         y
              x
                    Segment 0

                        Segment 1

                           Segment 2



The “standard” CsIElement has its long axis in the x-direction, so is x-measuring.
Segment number increases as x increases.

16 Aug 2002                                  2                          J. Bogart
                               CALLayer

z



        y

              x

                                                                   Log 2
                                                                Log 1
                                                             Log 0

              Segments 0   1   2 …


The CALLayer volume is made by stacking CsIElements in the y direction. Log
number increases as y increases. Hence for CALLayer both segment indices and log
indices increase in the proper direction.
16 Aug 2002                                3                        J. Bogart
              CALLayer Rotated
                                                               …     2      1      0    Logs



z



        y

              x                                                                 Seg 4
                                                                         Seg 2

                                                                   Seg 0



If CALLayer is rotated so that +x goes to +y, the segment ordering increasing in the
proper manner but the log indices are backwards.
This is not how the y-measuring layers are created in the XML description.

16 Aug 2002                                  4                             J. Bogart
                  CALLayerYMeas

z
                                                                                Log 0
                                                                               Log 1
                                                                             Log 2
        y

              x




              Segments 0   1   2 …


CALLayerYMeas is made just the way CALLayer is, namely by stacking CsIElement
in Y, except that the log numbers are assigned in the reverse order. Unrotated
CALLayerYMeas has segment numbers increasing in x, log numbers decreasing in y.
16 Aug 2002                              5                       J. Bogart
     CALLayerYMeas Rotated
                                Logs   0    1       2



 z



         y

               x                                                               Seg 4
                                                                       Seg 2

                                                                   Seg 0


If CALLayerYMeas is rotated so that +x goes to +y, the segment ordering increasing in
the proper manner (with increasing y) and the log numbers increase with increasing x.
The XML description in use alternately stacks CALLayerYMeas and CALLayer
volumes.
 16 Aug 2002                                    6                          J. Bogart

								
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