[Halld-tracking-hw] NO FDC meeting tomorrow Thu 12/19

[Lubomir Pentchev]

Dear all,

Most of the people are already in vacation, so I will cancel this meeting.

Significant progress has been made in the Hall in the past two weeks. All 
the LV cables have been connected to the FDC and temporary to the LV 
panel. LV  has been applied for many days to all the channels. There are 
no problems  at the  detector side, just a minor problem  with one 
connector at the LV  panel. The cooling system is working fine all the time.

Since the end of the last week we are flushing the FDC using
Ar/CO2 90/10 pre-mixed bottle. This week we started applying HV 
to all the chambers. One negative HV module had to be replaced: could not 
regulate the voltage on three channels. We have same problem with one of 
the positive HV channel and will replace that module, as well. All 
channels have now +1600/-200V which is about the nominal for this gas 
mixture. A couple of channels are not stable yet but I think they will be 
fine at higher gas flow and with the 40/60 gas mixture. We also tested all 
the HV connections by looking at the signals from one (per cell) long strip, 
and turning on/off the HV channels. There are no problems, but in this way 
we could test only the positive HV.

By the end of the week we will disconnect the LV cables and bundle each 
quadrant separately, so that we can continue with the signal cables next 
year.

Happy Holidays,
  Lubomir