Transcript Status of INFN Chamber test at CERN

Status of INFN Chamber
Test at CERN
M. Anelli, W. Baldini, G. Graziani,
M. Lenzi, A. Massafferri,
R. Nobrega, D. Pinci,
F. Rodrigues, C. Satriano
Chamber test
• All chambers have to be re-tested at CERN
after dressing in LNF
• 125 Chambers arrived at CERN on August 10:
– 6 M5R2
– 22 M5R3
– 97 M5R4
• All chambers have been already tested for
gas leakage and High Voltage up to 2700V
• FE test in progress..
Test Setup
Tests are done on
eight trolley used
for transportation
All chambers are
continuously flushed:
chambers in a trolley
are flushed in series
while all trolleys are
flushed in parallel
Gas Test results
• 112 chambers without problems
• 6 chambers were leaking from gas pipes and
are being fixed by replacing gas connectors
118/125 chambers are OK
• 7 chambers ( 5 M5R4 + 2 M5R3) are still
leaking and are currently under investigation
From now on, a gas test is foreseen in LNF
before shipping to understand if leakages
come up during dressing (more probable) or
during travel
HV test results
• 100 chambers have reached 2700V without
problems (current per gap < 10nA)
• 7 have been cured by conditioning at reverse
polarity
• 3 have been cured by cleaning or removing
external glue on hv bars
110/118 chambers are OK
• 5 are currently being conditioned at reverse
polarity (each one has one gap < 70nA @2700V)
• 3 (M5R4) have one gap with big discharges at low
voltage: bubble? Under investigation…
FE tests
• All chambers tested in LNF without HV:
all channels had electronic noise less
than 5 KHz at th=12fC
• Retesting at CERN in progress..
• One chamber given to Anatoli for test
on mock-up with cosmic (see his talk):
one FE board noisy, had to be replaced
• Test all chambers with cosmics? To be
discussed…