Happy Holidays! The chambers have performed well during the first E1
running period. It's a risky business giving out kudos because with a group
as large as ours it's easy to forget someone.
But we all deserve it, so here goes.
***************** KUDOS and STATUS REPORT ***********************
Monitoring - Richard, Dan, Junho, Jerry, Liming, Dave T., Mark I.
We are now able to quickly spot malfunctions and identify the faulty
apparatus.
Geometry - Francois, Alex, Rob, Larry, Junho, Joe
The survey data on chamber location is now in the MAP data base and
will soon be implemented within RECSIS.
Tracking - Franz, Jim, Rob, John, Joe, Jerry
Hit-based tracking is working well after major changes to clean up the
software and to improve efficiency by not requiring that all six
super-layers have a found track segment. Time-based tracking is more
modular with the addition of an intermediate DC1 bank which contains
times from which all fixed delays have been subtracted. This modular
approach simplifies future schemes to remove isolated hits and to handle
dead and hot spots.
Time Calibration - Francois, Franz, Liming, Burin, Joe
Much progress has been made in analyzing pulser calibration data and
entering the results into the MAP data base.
Laser calibration - Ross, Rory, Burin
The laser calibration system works; it records the maximum drift time
as well as pressure and temperature of the gas. It operates under PC
control and writes to its own disk file.
Gas System - George, Wayne, Mike, Steve, (Larry, Reinhard, Howard)-committee
A review of the gas system revealed that it is essentially complete but
pointed out areas of concern in pressure and flow control and in
calibration procedures for the instrumentation.
High Voltage - Vardan, Dan, Gail
The high voltage control program works and is well-documented.
Low Voltage - Christiana
The low voltage system is relatively trouble-free and remote monitoring
works but is not yet totally reliable.
Pulsing - Jeff, Dan, Burin
Remote pulser control works.
Operations - Dan, Richard, Rob, John
NUMEROUS problems have been identified and fixed and operational
procedures established.
Raw data - Dave, Serguei, Burin
A new status bank continuously monitors the raw data from the crates.
Chamber repair - Dan, Steve, Richard, Reinhard, Rob, John, George, Michael
Many problems have been fixed, most associated with broken wires.
Electronics repair - Chris, Bill
Problems with the ADB's and TDC's have been efficiently fixed.
*************** CALIBRATION WORK for JANUARY **********************
Pulser Data Analysis - pulser data has been taken in December. It must be
analysed for fixed delays and for wire status.
Signal Propogation along Wire - data from different phi values must be analyzed
to experimentally determine the signal propogation velocity along the
sense wire.
Time Walk - time spectra (corrected for fixed delays) must be compared for
different values of gain. Differences in the spectra (at small values
of time) can be attributed to time walk.
Particle Time of Flight - a careful check of the time of flight corrections done
by the SEB package must be carried out.
Drift Velocity - an automatic procedure for fitting the distance to time
correlation for a subset of the data must be developed.
DC Mis-Alignment - after fixed and event-dependent time delays are determined
and entered into the MAP data base, and after the distance-time
correlations are determined and entered into the MAP it will be
necessary to introduce additional displacements and rotations to the
chamber positions in order to optimize momentum and angular resolution
on tracks.
*************** TRACKING IMPROVEMENTS for JANUARY *******************
Hit-Based Tracking - include track segment direction as well as position
- use only 4 superlayers plus target position
- use only 4 superlayers plus other track's vertex
- account for small dead areas
Vertex Constraints - form an event vertex
- develop vertex-constrained tracking
- develop code to find secondary vertices
Time-Based Tracking - study efficiency and resolution versus luminosity
******************* 1997 ORDER of the WIRE Award ***********************
Many people have contributed much work to the CLAS drift chamber
project, but the award for the BEST drift chamber group member of 1997
goes to
********** DAN CARMAN *********,
for service and dedication WAY beyond the call of duty.
Dan's feel for the correct priorities, careful attention to detail,
insistence on quality work from his colleagues and his loving care
of the chambers made this a successful year.
We are all very grateful.