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Archived Messages for CLAS_OFFLINE@cebaf.gov: Drift Chamber Alignment

Drift Chamber Alignment

SCHUMACHER@ernest.phys.cmu.edu
Mon, 26 Jan 1998 16:23:47 -0500

Drift_Chamber and Off-line Folks:

As of this afternoon (2pm 1-26-98) the CLAS drift chamber
alignment using survey data is in place in the generally-used map
(DC_GEOM.map). To use this information successfully you need to remake
your Recsis, with either a cvs checkout or an update of your dc area.
The alignment changes have been tested over the weekend (by Stepan) and
have been shown to significantly improve our W resolution, as well as
removing some false correlations seen in the data. If you do not remake
your Recsis, your resolutions may get worse.

The drift_chamber people will get the full text of CLAS-Note 98-002
appended to this message which describes details of what was done. The
off_line people can get a copy of the Note if they care to read about
the details.

Regards, Reinhard.