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Status ATLAS SCT 2002

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Title: Summary of TDR: Placement Author: Paul Kuipers Last modified by: Nigel Hessey Created Date: 10/7/2001 1:23:14 PM Document presentation format – PowerPoint PPT presentation

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Title: Status ATLAS SCT 2002


1
Status ATLAS SCT 2002
  • NIKHEF Contributions to ATLAS
  • Magnets discussed by Frank
  • Trigger
  • DCS
  • Muon MDT and alignment Covered by next talk
  • SCT
  • Talk Outline
  • SCT Progress Past Year
  • NIKHEF SCT Work Past Year
  • Future NIKHEF Work

2
ATLAS Detector
3
SCT Progress Barrel
  • 1st Carbon Fibre Cylinder Delivered
  • Mostly in spec, some difficulties achieving the
    very high precision machining requirements they
    had
  • Ready to start mounting brackets
  • Some delay because of last minute change in
    layout for clearances
  • Modules
  • UK and Japan sites qualified for production
  • Nordic Group and USA have made modules but still
    not perfect
  • Japan in routine production since summer 2002 and
    now speeding up
  • UK started routine production
  • System Test
  • Many modules run simultaneously
  • With good grounding and shielding, no extra noise
    and good rejection of external noise

4
Barrel System Test
5
SCT Progress - Endcap
  • Modules
  • Hybrids K4/K5/KB/Filters story
  • Mid 2001 realised K4 had serious problems
  • Started program to be sure of solving it
  • 1. Investigate/understand the problem difficult
    with binary (hit-or-miss) readout
  • At NIKHEF we realised it is a feedback from
    Digital Power Supply to Analogue side
  • 2. Fix K4 (NIKHEF)
  • Filters in digital power supply
  • Worked well on NIKHEF modules, but could not
    rescue a Liverpool module
  • 3. New version K5 (Freiburg)
  • 4 layer ? 6 layer better AGND plane
  • Now working well
  • 4. Fit Barrel Hybrid on Endcap Module KB
    (Geneva)
  • Worked as well as Barrel Modules (still some
    feedback)
  • Cooling finally worked well, but more material
    and ?cost?
  • Would have been a lot of extra engineering work
  • Decided early 2002 to go ahead with K5

6
Feedback Model (S. Peeters simulation)
7
Feedback Reduction with Filter Glued on Chip
  • S-curves Before Filter

After Filter
Filter Circuit glued to ABCD Chip Joop
Roverkamp/Henk Peek
8
Radiation Hardness of Endcap Modules
  • June 2002
  • Two Endcap Modules Irradiated
  • Very noisy, out of spec
  • Optimists Maybe they got overcooked?
  • August 2002 Two more irradiatedbehaviour much
    better, well inside spec
  • Pessimists Maybe the August ones were
    undercooked
  • The Pessimists were right
  • Status now
  • Some chips out of spec on irradiation most OK/on
    the edge
  • Are Endcap modules worse than Barrel? (I.e., is
    K5 bad?)
  • Dont know any mechanism why they should be
  • Hybrid power supply lines all OK after
    irradiation
  • Could be statistics? Barrel were lucky?
  • Fix We can raise threshold from 1 fC to 1.2 fC
  • Fixes noise rate little effect on efficiency or
    tracking
  • Raise bias to 450 or 500 V
  • Regains full charge collectione efficiency
    Modules hold this HV

9
NIKHEF SCT Progress
Module Noise Model Simon Peeters
  • In addition to feedback also has calculated the
    fundamental noise limit
  • Many significant contributions
  • Many input parameters, some were unknown and had
    to be measured
  • End result
  • Modules are 10-20 noisier than predicted
  • Best quality chips are closer to prediction
  • Conclusion we have a good hybrid, close to ideal
  • Butstill some things not understood, e.g.
    anti-noise at low signals

Chip-0 Output Noise
10
Module Manufacture 5 Inner K5 Modules Made
  • Aim was to test K5 and develop assembly
    techniques and QA
  • All are in specs most important parameter within
    1 micron
  • Sent to test centres
  • 3 to system test
  • 1 for thermal tests
  • 1 for irradiation

11
Discs
  • Order placed with PCI in July 2002
  • First 2 Discs Delivered Last Week
  • DU01 In Spec
  • DU02 Not flat enough
  • Needs work with PCI to see what can be done
  • Cylinder and Wings contract imminent
  • NIKHEF Cylinder due July 2003
  • Cheap-O Prototype
  • Torlon Inserts Succesful
  • 300 per disc low X0
  • Now glued to disc
  • Next machine flat
  • Send to UK for Services tests

Flatness of DU01, side 1 0.4 mm
12
Cheap-O with inserts, ready for measurement
13
Tooling to machine discs flat
  • Discs 0.5 mm flat Modules need better
  • For placement For Services Clearances
  • We machine inserts to 0.1 mm flatness
  • Stiff-back rohacell sandwich made
  • Most fittings made
  • Ready Feb 2003

14
Future NIKHEF Work
  • NIKHEF Site Qualification
  • We make five more modules in Jan/Feb
  • If all OK, we are ready to receive components and
    start manufacture
  • These 5 modules can go into ATLAS
  • Endcap Module Production
  • Officially starts April
  • Hybrid delayed thoughlooks optimistic
  • Discs
  • Sort out flatness
  • Finalise disc layout details
  • Test services, inserts etc. incorporate minor
    improvements
  • Start machining discs

15
Disc Assmbly
  • H026
  • Glue inserts
  • add services

16
H023/24/25 Assembly
  • Module assembly
  • Modules-to-disc
  • Disc-to-Cylinder
  • Testing
  • C3F8 Evaporative Cooling
  • Whole disc readout

17
The End 2005 Ship One Endcap to CERN
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