DC operations manual: I've started writing an ops manual in LaTex format.
I'll send it out to the group. Please read it and send me comments.
The goal of the document is to instruct a non-expert to operate the DC
high voltage, to attend the gas and HV alarms, to monitor the overall
performance of the DC's, to spot problems, identify their location and
to either fix them or call the expert.
Pulser system: two improvements are being made. First, the ADB boards are
being revised to match the polarity of the 16-SIP calibration trace on
the Reg. 1 STB boards. Second, the level generation for the Enable/Inhibit
selection on the TCI boards is being shifted to VME control.
High voltage control program (DCHV): Vardan Gyurjyan has produced documentation
for his program, DCHV. Gail and I are working with him on improvements
for December.
Electronic malfunction repair: Dan has repaired all (?) of the
electronics problems which are accessible. Most involved malfunctioning
ADB or MUX boards or various kinds of disconnections.
11th crate: Dan is coordinating work on instrumenting the backwards Region
1 wires into the 11th FASTBUS crate.
Pulser run: time calibration: Franz is coordinating the final pulser
calibration using the utility RECCAL, developed by Francois.
Goodbye, Francois: Francois Roudot has completed his two-year post-doc
with Saclay and has returned to France. He did an outstanding job implementing
the calibration initialization in RECSIS as well as writing the utility,
RECCAL, which analyzes pulse calibration data and writes the time delay
and status word for each wire to a MAP-managed data base. RECCAL is also
the clearing house for other programs, such as PDU, to enter status information
about wires into the MAP data base. Bon chance, Francois.
Geometry and survey issues: Region 1 has been re-surveyed. The results show
that it is where it was (wherever that is?) within 2 mm. Larry and
his student Rustum are analyzing Region 2 survey data. Early data indicate
that the Reg. 2 chambers are all located at the same place (to +- 1mm)
relative to the cryostat. Alex Skabelin previously reported the the Reg.
3 survey results. Unlike Reg. 2, Reg. 3 chambers differ in their relative
position by +- 10 mm. One of the largest effects is that sectors 1 and
4 are lower than nominal by about 10 mm presumably due to support posts'
bending. Alex, Franz, Joe Manak and Rob are now fixing RECSIS to incorporate
true 6-fold geometry (presently, one sector is calculated and used for
all sectors' data). Rob has taken the in-line parameters which describe
the internal DC geometry and put them into a BOS bank with Joe's help.
This is part of a larger effort to make a common geometry available to
other utilities, like CED, GSIM, etc.
Gas system review: We are holding a review of the gas system on Nov. 20
and 21 (next Thurs. and Fri.). The review panel is Howard Fenker (det. group,
chair), Larry Weinstein, Reinhard Schumacher, Brian Kross (det. group),
and Graham Smith (a chamber expert from BNL). Wayne Major and George
Jacobs will handle the presentations and the site tour. The agenda is
still flexible, but generally Thurs. morning will be presentations, Thurs.
afternoon - site visits and Friday is reserved for the committee to meet and
prepare their report.
CAEN visit: Mr. Catarsi from CAEN will visit CEBAF next Monday, Nov. 17,
to discuss malfunctions and spares, etc.
SSL tracking: Junho and Liming are creating a utility, single-superlayer
tracking, which will fit trajectories to segments in one superlayer.
It is needed for calculating efficiencies as well as studying the
drift-time correlation; in either case, without bias because of
chamber-to-chamber misalignment.
Vienna: The triennial wire chamber conference will be held in Vienna
in February. I am applying for a talk summarizing the CLAS drift chamber
system with emphasis on commissioning and calibration. We can also apply
for more talks/poster sessions, for instance on construction and design
details of individual regions. I'd like to coordinate our entries to give
us maximum exposure - please let me know asap of any plans to apply for
a contribution. Abstract deadline is November 30.
December run: just three weeks away! Our goal is take high-quality data;
to keep the system functioning, to record data-taking configurations in
the relevant data-base, to spot and fix problems quickly, all without
DC experts on shift. To do this, our utilities (MONITOR, RAWMON, RECMON
and PDU) must be working, easy to use and well-documented. Our CALL LISTS
must be complete and up-to-date.
Give me your feedback.
regards, Mac