Inner Detector Status

1
Inner Detector Status Planning

• In short
• We suffered another set-back due to faulty solder
  joints in the EC SCT HEat eXchangers (HEX)
  devices to cool down inlet liquid C3F8 with mist
  of outlet C3F8
• This has been overcome with the help of CERN
  services and a lot of good will of ID groups
• The heater refurbishment proceeds well enough to
  match the schedule (but always dangerously at the
  edge)
• Commissioning of cooling and ID-silicon continues
  to be an acrobatic exercise requiring a lot of
  flexibility and dedication (but with considerable
  attention to risk minimization)

2

• HEX installation was 90 complete on side SCT
  ECA (with near pipes already connected in Q3 and
  Q4) on Nov 1st.
• One break (while manipulating in SR1) and two
  leaks developed in a fragile junction.
• Fragile junction is here

HEXes in Q4A (54)
3

• Fragile junction 5?3mm pipes. The broken HEX
  shows bad solder joint

Solder joint (must penetrate through the
length)
5 mm OD pipe (inlet of liquid coolant)
3 mm OD pipe (goes into serpentine to exchange
heat)

• This was tested ok for pressure (25 bar), but is
  not an acceptable solder joint and is judged too
  fragile to sustain stresses which may happen
  during operation. Look at the others still to be
  mounted

4
3mm pipe invisible

• 70 HEX have the same problem, the rest has
  porous solder ?Must rework all.
• Potting did not qualify ? remove all
• Rework method qualified in CERN main workshop
• Problem due to excessive gap between pipes
  (0.25mm) inhibiting capillary effects
• Solved by squeezing external pipe end after
  annealing (gap 0.05mm)

5
Shorter overlap, better fill, thinner gap
Test welds in CERN main workshop showing
good solder penetration
X-ray of weld of one of the HEXes repaired
6

• Rework solder in CERN main workshop now done on
  7218 EC HEXes (ends today), cleaning and x-ray
  qualification follows immediately after (100
  success).
• Installation of HEXes 60 done (leak test and
  installation work follows the repair pace). We
  expect to end next week.
• Lost 4 weeks ? This hits badly the ID
  installation and commissioning plan.
• Plan is to seal both EC before Xmas and use Xmas
  stop to dry-out. This should allow a rapid
  sign-off of the ECs by mid January (but we must
  begin on Jan 2nd).
• We plan to hand-over to Pixel cabling on Jan 14
  (at least on one side)

7
Empty Underway Ready for test Tested
EC HEX installation dartboard- viewed towards IP
Update 28/11/2007 1900
8
Heater update

• Heater connector repair done on all in
  Thermocoax
• 93 heaters at CERN
• acceptance measurements and tests,
• weld new fittings (to match far heater layout),
• clean,
• x-ray,
• put TC on
• Repeat electrical measurements (R, IR)
• Install
• Connect pipes, leak test
• Commission control and interlock
• Run with coolant and sign-off (quadrant by
  quadrant)
• Remaining EC and 90 Pixel on their way to CERN
  (due today)
• We still miss 6 barrel heaters. Mix-up in
  Thermocoax priorities (!). Theyll be sent only
  Tuesday next... This is now further complicating
  the installation pattern (as the barrel layer is
  underneath the EC layer).
• Last visit to ThCx of Neal Hartman next week for
  wrap-up
• All endurance (pulses) tests done so far indicate
  no problem, same for repeated R, IR tests.
• ?One barrel heater shows open circuit at the last
  test before installation (Monday this week).

9

• It was ok before welding of endings done at CERN.
  Must investigate if arc-welding can do this (in
  case of accidental gnd connection)
• Open circuit is inside the connector
• to follow-up
• Contacts with alternate vendor (Watlow) advancing
  and we can soon launch the engineering study of
  an alternative heaters the production of some 8
  prototypes.

before
after
10

• Installation is proceeding according to schedule
  (i.e. end all SCT HEX and Heaters installation by
  X-mas).
• Parallel working on many fronts ( unreliability
  of Thermocoax) are the main limitations.

Heaters
HEX
11

• Pressure release system (hard limit to 6.0 bara)
  installed and tested.
• Some commissioning already done. Barrel heaters
  (Q4A, Q1A) have been run without/with modules on
  for a total of 100 heater-hours. New run with
  Q4(AC) and Q1(AC) planned for this week-end (
  6hrs of barrel SCT modules-on per day to debug
  new code and be ready for fast EC sign-off).
• Dry environment control improved (20 additional
  pipes inside cryostat bore) and run at 6 bara
  (Tmin 10C) is no problem (Tdew3C), it will be
  for 4 bara (Tmin 0C) needed for Pixel.
• Pressure drop sensibly smaller than expectations
  (along heater and from heater to rack). Must
  extrapolate to cold operation and check on all
  orientations, but thats good news.
• Priority to installation and commissioning of
  cooling, the SCT commissioning has to use time
  windows on short notice dedicated EC sign-off.

12
Cooling review milestones

• We work on them and we monitor them (on special
  meeting and at each IDSG)
• Some are done already
• pressure release system,
• Follow-up closely heater refurbishment launch
  new supplier
• Nominate Risk Analysis coordinator and start
  activity
• Sufficient humidity monitoring should be
  installed
• Some are advanced
• Strengthen ID level organization
• IDGEN organogram (see ID web page)
• Define a clear plan for commissioning (see ID web
  page)
• Some are initiated, but need EC closed to be
  finalized
• Study implications of N2 leaks

13
ID Organization for Commissioning

• Commissioning coordinators in charge up to end
  2008 run
• Pixel Mauricio Garcia-Sciveres (LBNL) ?
  Claudia Gemme (INFN-Genova)
• SCT Heinz Pernegger (CERN)
• TRT Anatoli Romaniouk (MePhi)
• IDGEN Steve McMahon (RAL) (Cooling/Environment)
• Pamela Ferrari (CERN) ? Saverio
  dAuria (Glasgow) (DCS/on-line)
• Christian Schmitt (CERN) (Off-line/trigger)
• Weekly Commissioning meeting of sub-detectors and
  two-hour weekly round table discussion of PL, PE
  Comm. Coordinators to
• monitor progress and define/adjust plan
• define availability and priority in use of common
  resources
• Daily morning meetings for the workers (during
  (close to) commissioning periods)
• Specific of each activity (e.g. cooling, SCT,
  etc.)
• define/optimize work of the day

14
Commissioning plans (mostly silicon)
Now moved 1 week earlier
15
Commissioning plan TRT
16
Conclusions

• ID installation and commissioning has been
  squeezed a lot as a consequence of the
  evaporative cooling problem(s).
• The TRT commissioning is well under control and
  only limited by ROD availability (50 in
  December, the balance Feb)
• The silicon commissioning plan is still very much
  embedded with the installation plan and
  commissioning of the evaporative cooling. To be
  successful it requires
• A complex organization with some flexibility
• 2 shifts/day from now on (and week-ends at least
  up to X-mas)
• Improved risk analysis and follow-up

17
The ID life has not been easy in 2007
sign-off the ID cooling
but we have reacted to a hostile environment and
saved the cheese so far
we sincerely hope
that 2008 will not see us again in the center of
the dartboard!
Good luck to ATLAS 2008!