Forward Electromagnetic Shower Calorimeters: Readiness for Commissioning
W. Brooks, September 1996
I.Detector Construction
*All six detectors have been completed, tested with cosmic rays, and installed.
*Cabling is underway. At least one sector will be cabled and tested by December;
currently all trigger and HV cables have been fabricated; 20% of the delay
cables have been fabricated and progress is rapid on these. Of the cabling
within the racks, all of the splitter-adc cables (shielded controlled impedence
cables) are expected to be installed in October-November, and the 'lemo' cables
will be available for at least one sector by December, the balance of these by
the end of calendar 1996. (The latter two items depend on vendors delivering
within a few weeks of 'on schedule'.). Some additional 'lemo' cables are also
available from the calorimeter cosmic ray tests. Twisted pair cable and
connectors are almost ordered, and come with a 3 week lead time. These are
currently planned to be fabricated at Jefferson Lab.
*All trigger electronics, adc's and tdc's have been delivered. All HV modules
have been delivered. All electronics delivered has been tested.
*Installation of forward carriage electronics has begun and is well underway.
Contributors include Cole Smith, Alan Coleman, TY Tung.
II.Online Monitoring
*Cole Smith has agreed to be responsible for online monitoring aspects of the
forward calorimeter. A set of diagnostic histograms has been presented to the
local calorimeter group and the software group and has been discussed. He is
currently developing the macros needed to view the standard set of histograms
using PAW as a viewer.
III.Triggering
*Ideas for trigger conditions desired for the December run were recently
discussed by the local EGN group. A set of five core triggers were tentatively
defined, in addition to a few other possible configurations. The core triggers:
1) define a 'minimum ionizing' event for B=0; for 'B=0.5', the other triggers
2),3) define electron candidate events to test the calorimeter and cerenkov
counter independently, 4) define events to be used to test the prototype Level
2 trigger, 5) random trigger.
IV.Laser Calibrations
*Kevin Giovanetti is planning to set up the calorimeter laser on the forward
carriage (Deck 4), connect fibers to the six distribution assemblies, and
take laser data, all as soon as data acquisition is working in some form
from the forward carriage.
V.Electronic Pulser
*TY Tung has agreed to take responsibility for the hardware and software aspects
of the electronic pulser calibration of the calorimeter adc's and tdc's.
VI.Status of Reconstruction Code
*Reconstruction software is working and has been exercised by Stepan Stepanyan,
TY Tung, W. Brooks, Cole Smith, Alan Coleman, Serguei Boiarinov, Alex Vlassov.
Serguei, Stepan, and TY have made important improvements to the code. See EGN
Calibration and Commissioning Newsletter #2 for details.
VII.Status of Commissioning Software and Documentation
*A new group has joined the commissioning studies effort: Dhongee Kim and his
student Min Jeong Kim will be doing an in-depth study of single pi+ production
on the proton.
*TY Tung has produced a semi-automated way to produce ntuples from BOS banks.
These will be used (at least at first) for calorimeter commissioning studies.
He has also continued to fix bugs in Celeg as they are discovered.
*W. Brooks is writing and testing code to make use of these ntuples for
calibration purposes, with a view toward having a functioning and tested
version for the December run. He has generated a number of long GSIM (GEANT)
simulations to be used in these studies, using the Celeg semi-realistic event
generator (includes elastic scattering and all resonances).
*Crashes of the CLAS GEANT implementation GSIM, which have inhibited the
commissioning studies for over half a year, are now much less of a problem
since it was discovered by W. Brooks that GSIM does not crash on the Sun
platform. Alex Vlassov may also have found a fix for the crashes on the HP
platform.
*Development of the commissioning software is still hampered by the lack of
reconstructed drift chamber variables. Currently for simulated data we are
using the event generator variables as 'fake' drift chamber data. This clearly
will hide some of the important features of event reconstruction.