> Title:
Alignment of the EMCAL Supermodules for year 1 with corrected geometry
> Date:
05.11.2010
> Subdetector:
EMCAL
> Report URL:
https://edms.cern.ch/document/1014917
> Version:
1
> General Observations:
Surveyed points on the EMCAL support rails are the only reliable
points to use. They are located at the rail ends, and we have a
relationship between these survey marks and the modules, assuming
that the detector as built matches the design. The relationship is
based on a simplified 3D model of the supermodule, which is an 8
cornered box, where 4 corners coincide with the eta = 0 end of the
modules and the other 4 corners are the survey marks. After
entering the positions of the 4 survey marks, the 3D application
CATIA gives the position of the 4 end module corners and the phi
variation between 2 adjacent supermodules.
The goal is to convert the points from CATIA to a
transformation matrix for the center of each virtual (software) SuperModule.
The virtual supermodules are also 8-cornered boxes, but the
dimensions are determined differently. The x dimension matches the
size of the strip modules, the y dimension is determined by the strip
module size and placement (the angle of the strip module changes the
position of its top-most edge), and the z length is currently 350.0
cm, which is approximately 42 cm longer than the active area of the
physical supermodules. This extra length is a historical artifact from
the development days of the detector.
Point name format is SMVolumeID_CATIAPointID.
> Coordinate System:
ALICEPH
> Units:
m
> Nr Columns:
7
> Column Names: (choose one)
Point Name,XPH,YPH,ZPH,Point Type,PrecisionXY(mm),PrecisionZ(mm)
> Data:
40960_00 -0.709 4.312 0.000 T 1 2
40960_01 -0.714 4.318 3.077 T 1 2
40960_10 0.730 4.333 0.000 T 1 2
40960_11 0.726 4.340 3.077 T 1 2
40961_00 0.730 4.333 0.000 T 1 2
40961_01 0.735 4.327 -3.077 T 1 2
40961_10 -0.709 4.312 0.000 T 1 2
40961_11 -0.705 4.307 -3.077 T 1 2
40962_00 -2.158 3.801 0.000 T 1 2
40962_01 -2.170 3.809 3.077 T 1 2
40962_10 -0.807 4.299 0.000 T 1 2
40962_11 -0.817 4.304 3.077 T 1 2
40963_00 -0.807 4.299 0.000 T 1 2
40963_01 -0.797 4.295 -3.077 T 1 2
40963_10 -2.158 3.801 0.000 T 1 2
40963_11 -2.147 3.794 -3.077 T 1 2