Stave Development Project 24 -Jan-2005 US ATLAS SLHC

Stave Development Project 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 1

Occupancy • At 30 cm an SCT module covers 0. 25% of the barrel surface area. • For present SCT region, modules will have to be modified to meet old occupancy and merged cluster targets – Increased segmentation • Finer pitch (increases channel count per module) • Shorter strips (increases number of modules) • Re-visit binary vs multi-bit front ends for cluster merging? • For TRT region need guidelines for width x length, extrapolate from SCT, scale to 1035 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 2

Occupancy • Even at large radius will need considerably shorter strip lengths to meet low occupancy specifications • Need to optimize module width vs length with concerns for – Material – Signal/power distribution, reliability – Cooling • Typical “Outer (TRT) Region” module size could be 4 cm (wide) by 6 cm (long) • Single module design model still valid at all radii? 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 3

Elements of an SLHC Tracker • < 20 cm: inner, dose: 1016 /cm 2 – new technology • 20 < r < 50 cm: intermediate, dose: 1014 -1015 /cm 2 – pixels, short strips, strip-pixels – modularity, mass, reliability, system issues – 60 m 2, 4 K “SCT modules” • > 50 cm: outer 1012 -1013 /cm 2 – strips – modularity, mass, construction logistics – 140 m 2, 16 K “SCT modules” 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 4

1070 500 300 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 5

Development of Tracking Structures • Address here the SCT region and the replacement of the TRT with silicon strip modules. • The modularity required or adopted will be effected by a number of factors – – Experience from present SCT effort Radius, occupancy, simulations Material Assembly logistics, cost, and schedule • Starting concept is a stave (multi-module) structure as was studied for Run 2 b • Effort funded so-far with 1 -time Do. E allocation 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 6

Stave Conceptual View • 2 sensors + hybrid = 1 module (ladder) • 3 modules per side • Modules linked by embedded bus cable and readout token passing scheme • 2 sided – axial/stereo or axial/axial • 1 Mini-Port Card /stave • Total length 66 cm • 3072 channels /stave Bus cable is Cu/Kapton laminate with 100 um lines and spaces, Al shield layer. Distribute signals, data, power, HV 24 -Jan-2005 Hybrid fabricated on Be. O For low mass and thermal Performance. Use advanced fine pitch design US ATLAS SLHC Tracking Meeting 7

Stave End View Silicon Sensors 4 mm separation Peek Cooling channels 2. 9 x 5. 6 mm Carbon Fiber Skin Hybrid electronics Foam Core Material/stave: • 1. 8% RL • (compare 2. 5% ATLAS) • 124 grams 24 -Jan-2005 Fraction of Total RL: • Hybrids 13% • Sensors 39% • Bus Cable 17% • CF/Coolant 29% US ATLAS SLHC Tracking Meeting 8

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Phase 1 Stave (Outer Region) 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 10

Phase 1 • The purpose of Phase 1 is to gain experience with ATLAS style electronics on a multimodule structure • This design is not far from a conservative SLHC stave for the TRT region • Expect a real design would re-optimize strip length and axial-stereo aspect. 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 11

Hybrid and Interconnections Key initial task is the design of a hybrid and bus cable for the ABCD chips 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 12

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Phase 1 Milestones (completion dates given) full electrical specification and schematic for Phase 1 stave 10/04 establishment of test stands at LBNL, and Hampton 11/04 validation of test stand operation on test parts 12/04 design and layout of Phase 1 hybrid 12/04 fabrication of hybrid 03/05 assembly and test of hybrid 04/05 re-commission and tests with existing fixtures 03/05 assembly of ATLAS staves 06/05 * initial test of ATLAS staves at LBNL 07/05 transfer to and test of staves at BNL/Hampton 08/05 irradiation studies of staves 10/05 transfer of assembly methods to BN 07/05 24 -Jan-2005 US ATLAS SLHC Tracking Meeting done LBL 1/05 4/05 5/05 14

Status • • • Check prints for hybrid in-hand ~30 days for revisions and review Order substrates Fabrication order requires additional funding Begin bus cable layout 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 15

Stave Assembly • For Phase-1 use inherited fixtures from FNAL • Procure dummy wafers and hybrids for tests (in progress) • Start to consider new fixture set for Phase-3 • Look towards automated process using motion control and vision • Try to understand work-flow and load to determine scale, requirements, and cost of a production process 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 16

Stave Assembly Fixtures from FNAL Module holders Hybrid, fanout attach fixture 24 -Jan-2005 Stave assembly fixture Glue transfer plates Stave bonding fixture Transfer plates US ATLAS SLHC Tracking Meeting Test boxes Module assembly Fixture (sans stages) 17

Assembly and Test Process • Hybrids – Printed substrates inspected and probed – Component attach, wirebond – Inspection and test • Staves – – – Glue hybrid and fanout to detector (= module) Wirebond Test Glue 6+6 modules to stave, wirebond Test 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 18

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Phase 3 • This is an out-year effort FY 06 • Configuration, region, radii to be determined from earlier phase work and simulations • Considerable component and fixture development will be required. 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 21

Strip-pixel staves (Phase 3) 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 22

For strip-pixel layer two sides Independent, therefore thicker stave is more appropriate 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 23

Comments on Strip-Pixel Staves • As detector becomes short hybrid covers much of the surface area • Be. O-gold thick film technology while robust is probably too massive • These issues are currently of concern to the strip layer development for PHENIX at RHIC, that effort should be monitored – Their present approach is probably unrealistic! 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 24

PHENIX Strip Detectors Sensor elements: Developed at BNL Two strip-pixel arrays on a single-sided wafer of 250 (400) µm thickness, with 384 channels on 3 x 3 cm 2 area. Initial design: “longitudinal” readout. Made by SINTEF Pixels: 80 µm 1 mm, projective readout via double metal XU/V “strips” of ~3 cm length. Strip Read-Out card (ROC) new design: “lateral” SVX 4 readout. Made by HPK Strip ladder: 5 (layer 3) or 6 (layer 4) sensor+ROC 12 SVX 4 per sensor R&D at ORNL 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 25

Issues • CDF Be. O hybrid – 1. 11 %Xo realized • PHENIX assumes thin Al layers for power and signals and no substrate – 0. 411 %Xo – Issue of voltage drops along stave – With no substrate have assembly and reliability issues – Need a shield layer between hybrid and strips – With no substrate hybrid on strips will significantly increase source capacitance of input! 24 -Jan-2005 US ATLAS SLHC Tracking Meeting 26