- I am keeping a list of
which sets have been processed at the old talk page. Of interest
at the moment is one of the IMU
sets. 9 of the toroid scintillators are not within the mother
volume. This turns out to make no great difference, since we don't
use these even for tagging right now, but since they looked easy to
understand I tried them first. The answer seems to be that the
bottom containment volume wasn't rotated correctly about Y. Since
they appear symmetrically it wasn't obvious from the display.
- Some of the iron is also not contained within the mother volume,
which is probably true--it was tricky getting things sliced up
properly. I relied on the display, but that can be deceptive.
- Some of the parts of the BMU cells overlap. To get a feel for
what is involved, look at the points of overlap
between an Al shim and the cell body. I'm looking at roundoff-errors
here, and the only way to solve it is to make one of the volumes slightly
smaller: and I'll pick the shim.
- In other cases
cells overlap, apparently at arc boundaries. The
rotations are ideal, but the positioning is based on the true arc
positions. This will probably have to change. There are only a few of
these--most of the overlaps are from the shim/cell boundary.
- The rather complex chunks of iron just above and below the vertical
sides of the snout were enclosed in a BOX rather than a TRAP, and
consequently overlapped the neighboring volumes. I have a solution for
this, and better alignment for some of the other snout pieces which
also overlapped each other. Except for the SNOZ/SNOA overlap, I think
I have understood all the snout issues. The ImuContainerCore has an
outer radius of 150. cm, and the ImuContainer has an inner radius of
150. cm. Roundoff errors cause overlaps.
- However, the upper ImuContainment volume overlaps the CX00 and CX10
CMX volumes. This is real. Both have nominal radii of 405 cm, but the
IMU is shifted in x by nearly a cm, and consequently overlaps the CX
volumes.
- I am not at all certain what is happening with the SSOZ/IMH2 decontainment.
Gverify dumps 35 parameters instead of 12 for SSOZ, and the placement
seems completely wrong, judging from the positions of the overlap hits.
However, the display shows it in the correct spot. I suspect an issue
with byte ordering in Gverify has it confused.
- I made changes to the snout, core, and shims; and am rerunning
Gverify on a reduced file for the IMU, or at least what I think is
the IMU (it was last time). I expect the job to finish Monday.
Modified 5-December-2003 at 11:10
http://hep.physics.wisc.edu/~jnb/imu/26Nov2003
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