Results from the Straws
Straw Tracking Residual Study
September 27, 1996
These plots compare the positions of tracks in the PWCs to track stubs
in the straws. These plots were made using muon data. The straws were
run at 1550 volts which is still a fairly inefficent region
(see the
platau study), but with the low track multiplicity of muon data
misassociation background rates are not a big problem as they were in
the straw hit
residuals made on photon data.
As I see it the major work left to be done is as follows:
- High voltage platau study with traking.
- Threshold study with tracking.
After these two studies are complete the straws will be ready to take
real physics data. Further studies will be needed to improve
offline reconstruction:
- Time profile studies to determine t0 and drift velocity straw by
straw.
- Absolute tracking efficiency as measured against the PWCs.
Residuals which have been corrected by using an appropriate x offset are
shown below:
Jon Link, link@ucdhep.ucdavis.edu