Dave Kashy updated us on the state of the vacuum box. Plans are in hand and
construction should begin soon.
Abdellah Ahmidouch and Liping Gan gave an update on the dipole and magnetic
field mapping. A design for the precision mapper was presented and descussed.
Dan Dale gave an update on the design on the Pair Spectrometer. The design
now calls for staggerd finger placement using thicker scintillator in the downstream
counters. A sample light guide was shown to help explain the plan for shaping the
PS light guides. Results of some bench tests which measured the effective
transparency of guides with different shapes were also presented.
Mark Ito showed announced that the purchase order for the new dipole power supply
had been placed with DANFYSIK A/S. Delivery should be in time for the installation
period in the spring when the dipole is to be installed.
Sam Danagoulian gave an update on the light monitoring system. He discussed
using LEDs and an integrating sphere as a light source for the system.
Rory Miskimen gave an update on the target X-ray attenutation apparatus. They
were able to reduce the by ~25% by using a shorter NaI crystal. The target ladder
design was also presented and discussed briefly.
Rory Miskimen also gave an update on the Veto counters. The plan now calls for
2" XP2262B PMTs. Plans are being made for light guide construction and building
of a prototype counter at UMass.
Ashot Gasparian gave an update on HYCAL. Anitoli Sitnikov has been performing
tests of the thermal linear expansion coefficients of the crystals and candidate
materials which might be used for the flange which couples the phototube to the
crystal.
Liping Gan presented results from cosmic ray studies of the PbWO4 prototype as
well as linearity and stability tests of the PMTs (w/ bases). Non-linearities
of the PMT/bases were found which seemed consistent with those from the beam data.
Some proposals were made in how to address the non-linear behavior and correct it.
Rate tests were also done and the results presented. Significant changes(>10%) to the
amplitude were observed for two PMT types as rates were increased up to 50kHz.
David Lawrence updated the status of the trigger and readout electronics. The
biggest issues currently facing the collaboration are:
HV supplies: CAEN or LeCroy
Anode or Dynode signal for trigger (probably dynode)
Analog Delay chips
David Lawrence, Dennis Weygand, Sam Danagoulian, and Liping Gan presented updates on
the July 2000 beam test data analysis. The Pb-glass I data seemed the best quality
with a resolution of 4.5-6.0% over root E. The PbWO4 data was plagued with cross-talk
problems and non-linearities. The Pb-glass II data had trigger timing problems
which make the tagger very hard to calibrate. It is unclear whether or not the Pb-glass II
data can ever be useful.
Mahbub Khandacker showed a few pictures for Carlos Salgado that he brought back from
his recent trip to France. These showed how CMS was handling their PbWO4 crystals and
the specifications which they require.