Global Supports CDR 1 W.O. Miller July 2001 US ATLAS Pixel Detector Disk Ring/Frame Status Review W.O. Miller, R. Smith, W.K. Miller, R. Baer HYTEC G. Gilchriese, E. Anderssen, N. Hartman, F. Goozen LBNL

Global Supports CDR 2 W.O. Miller July 2001 US ATLAS Pixel Detector Fundamental Constraints Design Constraints Low mass –Composites, high stiffness to weight ratio Highly stable –Low CTE composites, insensitive to moisture Low percentage radiation length –Ultra-thin, predominately carbon material Materials compatible with high radiation environment –Low activation materials, radiation insensitive composites Composed of subsections to facilitate assembly –End sections for planar pixel disk assemblies –Barrel section for multi-layer of circumferential array of staves Insertable and removable in the ATLAS Detector –Registration and alignment to SCT requires indexing feature

Global Supports CDR 3 W.O. Miller July 2001 US ATLAS Pixel Detector Nomenclature Center Frame Section (1) End Section (2 ) Internal End Cone (2) (B-Layer and Services not shown) Interior Barrel Layers (3) Disks (6 ) Disk Rings (6) Disk sectors (8)

Global Supports CDR 4 W.O. Miller July 2001 US ATLAS Pixel Detector Disk Support Ring and Mounts Status WBS Ring Ring mount 8-sector disk

Global Supports CDR 5 W.O. Miller July 2001 US ATLAS Pixel Detector Prototype Ring Precision machined PEEK bushings for sector attachment P30 C-C facings YSH50 woven cloth/CE resin C-Channels Major departures from final design (1) 500mm dia frame design (2) Three point support with suspension point behind the ring (3) 12 Sector Disk

Global Supports CDR 6 W.O. Miller July 2001 US ATLAS Pixel Detector Ring Mounting Final Design Incorporates An Improved Radial Mount Concept –Connection of ring to the frame is accomplished with an adjustable mount made from PEEK material –Adjustment feature is used in the initial set up to facilitate the proper radial positioning of the disk Adjustable mount is bonded to the outer frame of the Global Support structure Differential screw feature is used to disengage the mount conical seat from the spherical ball –Upon re-assembly of the disk, alignment is achieved by adjusting the differential screw to its travel limit C-C bushing Sleeve bonded into bushing Spherical ball in a cone, 3 places View rotated for convenience

Global Supports CDR 7 W.O. Miller July 2001 US ATLAS Pixel Detector Mount Concept Disk Ring Mounting –Prototype testing at the disk level on a three support point design Larger diameter ring, more compliant Thermal and mechanical stability being extrapolated to smaller stiffer design –Four support points –Stiffness higher by a factor 10 Plans –As time allows, the new design will be evaluated on the final hardware Support Ring Radial Mount Prototype as tested Alignment pin Support ring

Global Supports CDR 8 W.O. Miller July 2001 US ATLAS Pixel Detector LBNL Ring/Mount/Frame Test Ring mounted in Global Support frame section by Fred Goozen –Tooling designed for precisely boring the frame and locating the three radial mounts for supporting the ring –Frame is supported on 8 columns, at the frame attachments points –Mounts are bonded in the frame corners (longitudinal tubes) Load testing –Static load applied at mid point between ring support points, duplicating technique used in previous holographic testing of ring –Load/deflection curve fit shows 22  m/N slope Previous HYTEC test of ring outside of composite frame yielded 17  m/N Small increase in compliance is ascribed to the mount/frame combination

Global Supports CDR 9 W.O. Miller July 2001 US ATLAS Pixel Detector Disk Support Thermal Tests 12 Sector Assembly Preparation for TVH Evaluation Sector 11 is approximately at mid span of the ring Approximate support points

Global Supports CDR 10 W.O. Miller July 2001 US ATLAS Pixel Detector Sector #’s Temp rise #11=1.35  C  Z=0.54  m  Z= 1.78  m Disk Support Thermal Tests Temperature sensitivity of out-of-plane sector motion ranged from 0.4  m/  C to 1.38  m/  C Disturbance above base of 0.4  m/  C largely caused by coolant tubing loads Blow-up of Full Disk Test Temp rise #13=1.29  C

Global Supports CDR 11 W.O. Miller July 2001 US ATLAS Pixel Detector 23.8  m/N tilt extracted from ring FEA. Note load was applied at mid-span on outer edge of ring, does not include the entire offset like in test (sector tilt is about 77.3% of that predicted by FEA) 18.4  m/N tilt across the sector, outside mid-edge to inner edge obtained by TVH Model Validation Sector #11 F F F-denotes area of load application in test Load points at edge of ring, 0.396N total

Global Supports CDR 12 W.O. Miller July 2001 US ATLAS Pixel Detector Ring Summary Salient points of Prototype Development –FEA approach to simulating ring design produced results that correlated with measurements –Conducted rather extensive testing of ring and mounts, including interaction with frame Tests included the actual proposed PEEK ring support mounts and the frame construction details –Based on the FEA and testing, a decision was made to increase number of support points from 3 to 4 Extraneous service loading on ring is not well known, this situation pushed the decision –Dimensional quality of the ring Reasonably good, but improvements are desired in the area of the C-Channel and the ring flatness Decision made to control the sector mounting pattern to provide interchangeability between any sector, and sector position –Method of precisely locating and bonding the ring mounts in the Global Support frame has been demonstrated by LBNL An average of 27 measurements taken on the ring in the vicinity of the three mount positions and they were found to be planar within 43  m –A modified set up and bonding procedure for the mounts is planned in the interest of achieving closer to 25  m This milestone eliminates considerable uncertainty in construction of the disk region Further tests will be conducted to measure the dimensional consistency in mounting, demounting, and remounting a ring assembly.

Global Supports CDR 13 W.O. Miller July 2001 US ATLAS Pixel Detector Ring Cost/Schedule $63,00016 weeks Phase III-Mold 6 sets of C-Channels and bond 6 ring assemblies $ weeks, with completion 4 weeks after Phase I Phase II- Fabricate all piece parts and fixtures for production ring, plus bond one assembly $ weeks Phase I- Demonstrate permanent mold tooling for improving Channel dimensional quality

Global Supports CDR 14 W.O. Miller July 2001 US ATLAS Pixel Detector Frame Status WBS W.O. Miller, R. Smith, W.K. Miller, HYTEC G. Gilchriese, E. Anderssen, N. Hartman, F. Goozen LBNL Outer Frame and End Cones

Global Supports CDR 15 W.O. Miller July 2001 US ATLAS Pixel Detector Final Frame Design Design configuration –Frame reduced from 500mm to 432mm diameter envelope Length tentatively remains the same at 1400mm –Mass estimate for dynamic and static FEA 2.85kg new frame structure, 21.04kg non- structure, total of 24.64kg 3.79kg old structure, 33.74kg non-structure, total of 37.53kg –Mass of inner barrel structures Layer 1 + Layer 2=1.55kg, counted as non- structural mass with respect to outer frame Early FEA pointed to the coupling between the shells and the end cones being soft, thus the inner shells and outer frame do not act in conjunction as a family of concentric shells –Structural mass of reduced frame concept does not include an end stiffener Design in process Design Studies

Global Supports CDR 16 W.O. Miller July 2001 US ATLAS Pixel Detector Overview Development Steps –Assessed construction options at the onset Chose flat panel concept over tubular frame primarily based on cost, but also construction simplicity, which equated to improved dimensional accuracy Simple, low cost tooling for assembly –Frame sizing exercise-via detailed FEA Selected sandwich construction parameters Selected sandwich facing and core materials –Constructed full size prototype of outer frame section Conducted extensive testing using precision measuring tool to confirm design and to validate Global Support Frame FE model –Constructing full size prototype of end cone---1 st unit complete Design Status –Resized frame to 432mm outer envelope dimension (compatible with insertion requirement) Design confirmation planned through FEA studies—complete Mounting aspects still under study

Global Supports CDR 17 W.O. Miller July 2001 US ATLAS Pixel Detector Outer envelope 432mm Length 1400mm Frame Dimensions

Global Supports CDR 18 W.O. Miller July 2001 US ATLAS Pixel Detector Frame Connections Exploded View of Outer Frame Connections –Alignment tube between sections –Fasteners retain End Cone to Barrel Section –Fasteners reside in recessed slots, which fix center section to Disk Frame sections Tie downs for services

Global Supports CDR 19 W.O. Miller July 2001 US ATLAS Pixel Detector End cone support of Layer 1and Layer 2 Cone flat panels End cone shell support fingers Inner most tab extension for B-Layer connection Nomenclature

Global Supports CDR 20 W.O. Miller July 2001 US ATLAS Pixel Detector Panel weight 84.3 g after removal of material (39.7% reduction) 355 mm long Frame Section---Disk Section Frame Prototyping Corner tube Holes for alignment pins Corner blocksVertex joint

Global Supports CDR 21 W.O. Miller July 2001 US ATLAS Pixel Detector 0.69  m/N 0.53  m/N Finite element model result Transverse Loading-Typical Load Case Corner region Peak distortion in corner Test Evaluation

Global Supports CDR 22 W.O. Miller July 2001 US ATLAS Pixel Detector Testing evaluated: –Stiffness at low strain levels, at level simulating the application Composite properties measured at higher strains, yet properties were used to design at low strains –Effect of bonded joints –FEA modeling approach for Global Supports Testing issues –Load Application Difficult to apply load without influencing measurement –Boundary conditions To test, frame is mounted to a base support structure –Objective is to limit compliance at base Frame Section

Global Supports CDR 23 W.O. Miller July 2001 US ATLAS Pixel Detector Development End Cone Salient construction points –End Cone for 500mm frame design –P30Carbon-carbon facings, ~0.44mm –XN50/cyanate ester graphite fiber honeycomb, 4mm thick –YSH50 quasi- isotropic laminate for outer supports and inner tabs Static component tests Individually, as well as mounted on frame White paint on short tab for holographic measurements

Global Supports CDR 24 W.O. Miller July 2001 US ATLAS Pixel Detector LBNL test results with end cone in place –Axial load 1.125inch from end of long tab  m/N HYTEC end cone separately –Axial load 1.125inch from end of long tab-- 16  m/N End Cone/Frame Test Note disk sector support ring Barrel section mounting tabs and dial indicator measuring displacement 12 Sector Frame-500mm dia.

Global Supports CDR 25 W.O. Miller July 2001 US ATLAS Pixel Detector End Cone Modifications Changes to structural geometry under consideration

Global Supports CDR 26 W.O. Miller July 2001 US ATLAS Pixel Detector Prototype Results Summary –Frame construction principles demonstrated Dimensional accuracy quite good, but improvement is expected by using low thermal expansion tooling option –End cone test results are somewhat troublesome Compliance of tab did not agree with FEA-work still in process to understand issue –Material options are well understood Stiffness Strength Radiation resistance –Current design process Down sizing outer dimensions to achieve insertable feature

Global Supports CDR 27 W.O. Miller July 2001 US ATLAS Pixel Detector FEA Model Mass Global Support Structure

Global Supports CDR 28 W.O. Miller July 2001 US ATLAS Pixel Detector Gravity Loading Static load analysis –Gravity sag –Torsional stiffness Results (24.64kg system) –Gravity sag, 12  m peak, with most of the strain occurring between the supports and the barrel region –Torsion- One corner unsupported, peak sag is  m Sensitivity, angular twist is 5.55  rad/N for corner load End reinforcement plate will not correct for either effect Simple sag Unsupported corner

Global Supports CDR 29 W.O. Miller July 2001 US ATLAS Pixel Detector Frame End Plate Choice for Achieving Increased Structural Dynamic Stiffness –Added end reinforcement plate at each end Static solution –Gravity sag decreases to 11.3  m –Torsion, one unsupported corner still droops 53.5  m, a 8.1  m decrease However, the 1 st mode is now 89.07Hz, an increase of 33.6Hz Vibration no longer an issue 89Hz

Global Supports CDR 30 W.O. Miller July 2001 US ATLAS Pixel Detector Effect of End Plate Noticeable reduction in stress and frame bending –Bending of frame member decreased from 4.7 to nominally 2 microns –Peak stress dropped from 8.2 to 1.28MPa (1223 to 186psi) Average stress was never very high Stress localized in panel Corner joint design margin –Enhanced by presence of end plate – Addition of end plate suggests that a 10 fold increase in moment capacity can be realized –Fastener loads Once location is fixed, fastener loads will be established and the design margin analysis completed

Global Supports CDR 31 W.O. Miller July 2001 US ATLAS Pixel Detector Barrel Layers L1 and L2 Global Supports/Barrel Interfaces –Status Interface control drawing exists Defines interface between the End Cone mounting tabs –Side A –Side C Layer L2 connects via 8-tabs to outer frame Layer L1 connects via 4-tabs to outer frame Issues/Remaining Work –Fold structural details of layers L1 and L2 Support Shells into Global Supports FEA –Update non-structural mass contributions in Global Supports FEA from layers L1 and L2 Need to add more detail on the B-layer

Global Supports CDR 32 W.O. Miller July 2001 US ATLAS Pixel Detector WBS and 2.3 Milestones Completed –Design envelopes for frame, end cones, disk support rings (including mounts), and barrel elements, L1, L2, B-Layer are complete –Finite element analyses of the component and system designs that validates the fundamental approach are complete –Prototype testing of all Global Support structural components are largely complete –Construction drawings for Disk Support Ring are complete –Construction drawings for frame are in process FY 2002 Planned Accomplishments –Complete construction of Disk Support Rings-procurement broken into 3 phases –Complete the end cone design –Solicit bids for all frame components –Pass Global Supports PRR –Initiate construction of frame components –In conjunction, tidy-up the Global Supports FEA models by incorporating final information on: Outer support shell/Global Supports connection B-Layer Support Tube/non-structural mass components

Global Supports CDR 33 W.O. Miller July 2001 US ATLAS Pixel Detector Project Schedule Data Global Support Status Summary –Basic design and analysis of all frame components complete –Completed CDR and FDR –Decisions on mounting and interface to support tube in process –General integration issues remain, relating mostly to service loads Topical Schedule Information  

Global Supports CDR 34 W.O. Miller July 2001 US ATLAS Pixel Detector Project Cost Data