Hi,
I found two errors in my reconstruction of the straight track data.
One was fairly minor: when editing I duplicated a line with the
offsets from tooling ball to target centres three times and changed
the offsets for the three chambers but neglected to change the index
for the array so the correct offsets were only applied for the inner
chamber and had zero offset for the others. The second was more
significant and rather stupid. I hard coded the transformation into
the chamber based system into my code using Aaron chamber positions.
Thus, even though I read in my new positions I still transformed to
Aaron's positions.
Fixing these two things I now see negligible (in my opinion) offset
in either sector. See figures below. Units are mm so the mean for
the left sector is at 13 microns and 68 microns for the right
sector. Note this is my definition of d which is 1/3 of Chris'
definition of d but even 3x13=39 microns and 3x68=204 microns is
probably too small to worry about.
Anyway, I have attached my suggested chamber parameter file and wire
parameter file so that perhaps people can try these to see if it
helps with the kinematics. One caveat. I have not corrected the
nominal B field or path length in the wire parameter file to reflect
the new chamber positions, etc. Will do this sometime and release a
new file.
I am still working on the cosmic straight track data but perhaps
these files can be incorporated fairly soon to see if they help.
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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