The following data files give the results of the CMM data from Allied
Mechanical who measured the chambers before shipping to MIT.
Each chamber was assembled, placed on a flat surface and roughly
oriented so that the machine Y axis was along the axis for the holes
in one super-layer. Thus for each chamber there are two files
corresponding to the two super-layers.
The CMM coordinate system has Z vertical but opposite to the Z we use
in the chamber based system thus X goes roughly along the line from
the 80 degree end of the chamber to the 20 degree end but parallel to
the top or bottom plate of the chamber depending on which super-layer
is being measured.
The data files are fairly easy to read but here are some tips.
The first line is the number of cells 18, 19, 26, 27, 34, 35 for
inner, middle, outer and superlayers 0 or 1.
Then they measure the 6 tooling balls (note these are different from
survey targets) on one side of the chamber. We don't use the middle
tooling balls as the chambers deflect after stringin the wires so
these move. We assume the ones at the ends don't move much. Then
they measure the TB's on the other side. Then they repeat these
measurements.
Then they start to measure the holes going first along one side of
the chamber and then along the other side. For each cell they measure
the holes for the three sense wires at two depths into the hole then
they measure the two corner guard wires for each cell again at two
depths. Thus there are 10 measurements for each cell measuring the
position of 5 holes. When they come to the end of each side there are
a final pair of corner guard wires to measure side so tere are 4
more measurements. Then they do the other side.
These files are the most complex but perhaps not so important. They
give the locations of the holes in the actual chambers relative to
the tooling balls. But in the end the conclusion is that the
chambers are made very well and the holes are where they are supposed
to be. There is a slight 3 micron shift in location per cell which
amounts to 100 odd microns over the length of the largest chamber but
its not too important.
Anyway, I applied these data to my calculations.
The file names are Inner, Middle, and Outer which are fairly clear.
The suffix 1, 2, 3, or 4 has the following significance. 1 and 2
refer to super-layer 1 3 and 4 refer to superlayer 0. Chamber 1 and 3
go to the left sector and 2 and 4 go to the right but the records are
a bit vague on this and maybe wrong.
If you do look at these files have fun.
Cheers,
Douglas
26-415
M.I.T. Tel:
+1 (617) 258-7199
77 Massachusetts Avenue Fax: +1
(617) 258-5440
Cambridge, MA 02139, USA E-mail:
hasell@mit.edu
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