From: Geary Eppley (eppley_at_physics.rice.edu)
Date: Sun Jun 01 2003 - 12:41:36 EDT
Hi All,
With the several run extensions, Bill was not able to get to BNL to
de-commission the pVPD so we need to do this on Monday. We also need to
disconnect and label the bridge pipes for the TOFr gas connection. This
only takes a few minutes. I'll meet volunteers in the physics building
about 9 am Monday morning.
Also, Hongfang suggested measuring the jitter in the full TOFr electronics
chain with a pulse generator. I think this is an excellent idea. We would
split a signal out of the pulse generator and send one leg on a short path
to the south platform to start the TDCs (and trigger daq?) and put the
other leg into two or more channels on FEE cards on TOFr. We would need
power on the south platform and LV to TOFr to do this. TOFr would have to
be removed from the detector and sitting on a bench.
We are not going to be able to do this before the Berkeley meeting but it
should be done once the detector is in the assembly bay and power is
restored to the south platform.
We would just need to measure the difference in stop times and the start
time would wash out. Since all the pulse heights would be the same in a
given channel, I think we would not need adc's or slewing correction.
This measurement would provide the benchmark against which the CERN HPTDC
daq system would be measured. It would also enable us to estimate
the intrinsic time resolution of the MRPC modules themselves.
Cheers,
Geary
Date: Sat, 31 May 2003 12:31:53 -0500 (CDT)
From: W.J. Llope <llope_at_physics.rice.edu>
Subject: Re: pvpd cables
also...
make sure plastic bag w/ all the short cables, splitters,
& buttons (all the small parts) gets into the tofp cabinet...
also you guys will probably want to wear gloves. they're
in the cabinet
thanks again!
Date: Sat, 31 May 2003 12:14:34 -0500 (CDT)
From: W.J. Llope <llope_at_physics.rice.edu>
Subject: pvpd cables
here's the comments on how to break down the pvpd cables...
thanks for this... w/ two people this could probably be
completed in ~1-2 hrs...
you need:
~6 pieces of bubble wrap, each ~12"x12"
~20 8" and 10 ~12-14" cable ties
snips
a plastic bag
nut driver (5/32"?) they're in the tofp tool box
make sure CTB HV supply is OFF
get up to pvpd east(west)
disconnect HV and signal cables from back sides of pmt assy
remove 4 nuts from FEE box and carefully disconnect 3 inputs to fee
remove those input cables and place in plastic bag
replace fee box cover
disconnect the D-section cables from the balanced splitters
**check each lemo connector - make sure the shell is not
unscrewing from the body - finger tighten if so**
_make sure_ the three balanced splitters are also put in the plastic bag
disconnect the timing path signal cables from the fee board outputs
**check each lemo connector - make sure the shell is not
unscrewing from the body - finger tighten if so**
disconnect LV bus cable
disconnect thresh bus cable
wrap bubble wrap around lemo connectors and use 3 cable
ties to firmly hold the bubble wrap in place. do the same
for the 3 HV cables (wrap separately). do the same
for the LV+thresh cables....
this was the key step. get to this stage on both sides
first.
then. if we want to be good civil citizens in star and
go the extra step (and you have another ~30min)...
start removing cable ties that last these signal cables
to things like posts on and under the balcony. do not
remove cables ties that are just on the cable bundle itself...
by removing maybe 5-6 cable ties, the cable bundles can
be pulled back down from behind the poletip carriage and
then just laid on the floor..
you can leave that flexible tubing on the bundles...
pull the tops off the plastic panduit boxes on the floor
and pull the cables out all the way until they
get the the cable trays bolted to the magnet steel.
stop there.
then straighten the cables out on the floor
then roll up, and use the big cable ties
to make this neat. its a fairly big bundle
(~2-3' diameter is tractable)...
the hv cables in one roll and all
the black cables are in the other.
last run i then took those big bundle
and used more cable ties to hang these from
the underneath of the lowest a cable tray bolted
to the magnet steel, and immediately above
the laser boxes. same location on
east and west.
this gets us totally out of the way,
and out cables are totally protected....
thanks again!!!
bill
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