MDT Commissioning in Atlas

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MDT Commissioning in Atlas
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Installation Sequence for 1/2 Barrel
0. BOF-BOG (installation fall 2004,
commissioning later in 2005) 1. BIS sectors 10,
12, 14, 16 (3 chamb/sect) 4 days 2. BIL
sector 13 (3 chambers, to ID serv.) 1 day 3.
BIS sectors 2, 8 2
days 4. BIL, ½ of sectors 1 and 9 2 days 5.
BIS, sectors 4, 6 2 days 6. BIL,sector 5 and
½ of sectors 3 and 7 3 days 7. Complete BIS
sectors 10, 16 2 days 8. BIR, BIM sectors 15
and 11, Except BIR 5,6 5 days 9.
BMS2RPC BMF2RPC
24 days 10. Complete BIS sectors 14 and 12 2
days 11. Complete BIL sectors 13, 9, 1, 7, 3 5
days 12. Complete EIL4 installation 8 days 13.
Complete BIR 5,6 in sectors 11,15
2 days 14. BML2 RPC
11 days 15. Additional RPC 2 days 16.
BOLRPC 8 days 17. BOS 7
days 18. EES EEL 8 days
After each installation step we have 4-6 days to
connect and check status Note that for the BIS
chambers after the BIL installation no access is
foreseen to FGs
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Test on MDT Chambers

• Gas system, HV, LV, DCS, and fibers should be
  available at installation time.
• Chambers should be already tested for
• Leak rate
• Noise and dead channels
• DCS (T sensors and B sensors) and Alignment
  components
• All the information on the previous tests should
  be available when we start the commissioning of
  the chamber
• All cables should be well identified and all
  chamber should have a map of T and B sensors
  positions.
• Acceptance test overground
• Connect the chamber to Gas system and HV, LV, DCS
  and read-out fibers
• Define how we connect the chambers at 3 Bar to
  gas line (use flow restrictor??)
• Check the newly made gas connection with portable
  leak detector
• Check temperature and B field reading
• Check in-plane alignment and sagitta compensation
• Check all axial-praxial and projective alignment
  components and cables.
• Rise HV to 2500 V to check for high dark currents
• Flow gas for few hours to restore the pressure
  and have a good mixture
• Rise HV to 3080 V
• Perform a noise and dead channels test
• Check correctness of cabling (how??)

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Why?

• Let me just remind you that
• Chambers at CERN coming from all over the world
  will be
• (some of them are alredy) in different
  conditions.
• say some of them are not equipped with gas
  or f.e. eltx
• 2) Cern test sites have the charge to deliver a
  fully working
• and tested chamber starting from the above
  conditions.
• Nevertheless
• Months will come by since a fully tested chamber
  will have to
• be delivered to the ATLAS pit.
• Moreover the detector need to be moved from the
  Cern test
• Sites to the Atlas pit.
• A last further and fast check (I think) is
  necessary

Paolo Branchini Università Roma TRE e INFN
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Time budget
A certain number of chambers per day (6?) will be
installed. As a consequence the time budget
devoted to the test is limited to more or less
one hour per chamber. Can we do something
usefull in such an amount of time? If yes how?
Paolo Branchini Università Roma TRE e INFN
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General considerations

• Suppose that
• Last usefull tests will be done on the surface.
• Then we could have 2 team one devoted to the
  tests
• overground and the other down in the pit
  for final
• connections and tests.

Paolo Branchini Università Roma TRE e INFN
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Synchronization with the cern test site
DAY installation day

• Cern chambers test site DAY-2
• Pressure check a simple manometer is needed since
• the chamber has been there for a long
  time...
• If pressure drop is compatible with atlas lost
  then the
• chamber can be refilled and delivered.
• Otherwise further check in the test site have to
  be done.

Paolo Branchini Università Roma TRE e INFN
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Atlas pit surface side
DAY installation day Since we have gas in the
chamber we do not need gas lines.
DAY-1
Pressure check (again with a simple manometer)
HV test HV crateHV
card. LV test Low
Voltage P.S. cables
DCS Mini
mastermuxCAN bussw.
LV test also imply 1 vme crate with TTC VI TTC VX
a PC with a gola card and 1 vme cpu optical
fibres. An effort could be done to collapse LV
and DCS test on the very same computer.
Paolo Branchini Università Roma TRE e INFN
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What if?
Pressure check says No? A damage has occurred
during last transportation. Chamber should go
back to the test site (could need days of
work). HV voltage test says No? A wire got
broken. We could easily use the chamber if we
accept to remove the resistor on the HV side and
lose one wire (1 hour work) we could do it
there. DCS says No? We will have an idea in
next future. Noise test says No? From a few
mintues to days of work it must be decided on a
chamber basis. If the problem is in the
connections between ground plates and pins the
Faraday cage must be removed WE NEED SPACE!
Paolo Branchini Università Roma TRE e INFN
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Time budget
Pressure check 2
minutes direct experience HV check
5 minutes direct
experience DCS check
10 minutes (hypotesis) LV test
10 minutes direct experience
Therefore we could do very elementary test on a
chamber with a time budget which is compatible
with 1 hour per chamber. Of course if everything
is fine then chamber is ready to go.
Paolo Branchini Università Roma TRE e INFN
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Conclusions
I personally think the above illustrated logic
is reasonable and should minimize the risk or the
chambers to be installed. The tools and people
in common with the test sites. The experience
coming from the chamber test sites will be
necessary and will further help to define the
procedure.
Paolo Branchini Università Roma TRE e INFN
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Necessary access zones for muon chambers
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Sector1
Access to Faraday cages
Sliding ladder
Electronic boxes
Platform
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Access to Faraday cages
Sector 3
Electronic boxes