Straw man layout for ATLAS ID for SLHC Issues to be discussed in the layout advisory group.

General Layout Aim to give a preliminary layout to the Eng. Groups and establish specification and list of options for further study. E.g. for installation scenario study – need to boundary conditions – length , radius etc. that are being considering. As a start assume the “envelopes” of the 3+4+2 layout for preliminary studies. For Eng. options the Working groups/R&D grouping will develop the specification and the implications of the Layout options.

Straw man Barrel Layouts b-layer integrated to the beam pipe. 1 layer at R= 5 cm. Granularity 300m x 50 m Z 2x40 cm Inner Layers - Pixels 2 additional layers at R=12, 18 cm Granularity 400m x 50 m Z length 2x 40 cm Middle Layers 3 layers at R=27,38,50 cm 4 Layers (27,38,49,60) Granularity 3.5 cm x 80 m Z length 2x100 cm Outer Layers 2 Layers R= 70,95 cm 2 Layers (75,95) Granularity 9 cm x 80 m Z length 2x190 cm

Straw man End-cap Layouts Discs 7 discs Pixel: Z= 50, 75 SS: Z= 120,165 4 layers 120,165,180 LS: Z= 210,260,320 Coverage in h Assume coverage up to 2.5 Moderator Need to optimize the amount of moderator on the EC face. The main difference between the two options is if one has 3 or 4 SS layers and 6 or 7 Discs. This will depend at the end on the optimization of the overall detector.

ID Straw-man Layout (4 SS layers)

ID Straw-man Layout (4 SS layers) 3 Pixel Layers 14,32,48 f Sectors 5,12,18 R Location 4 Short strip layers 22,32,40,48 f Sectors 27,38,49,60 R Location 2 Long Strip layers 32,40 f Sectors 75,95 R Location Moderator

Straw-man Options: Borated Poly – Locations and thickness. Fixed Length Barrel Quasi “Projective” layout. Integrated Pixel Implications of sensor layout options Mechanical Layout – options and questions Barrel Cylindrical support structure “ATLAS Like” + Discs “Staves” + Discs EC-Disc design Cooling Options Pressure, operating temperature

Borated Poly: Design for an integrated Luminosity of 7000 pf-1 Reduced the neutron flux/energy to minimize the damage to the electronics and sensors. Borated Poly can be placed in: Barrel Calorimeter Surface 5-10 cm EC Calorimeter Surface 5-20 cm Cavity in front of the Forward calorimeter. 5-20 cm Ref. Radiation Task Force Optimization: Ian Dawson Vince Hedberg Mike Shupe

Projective vs. “fixed” length Barrel “Fixed length”: All layers in same radial region have the same length in Z. Projective – each layer have different length. Projective: Smaller Si Area Material – needs detail engineering to comment if can be an advantage. Fixed Length: Easier assembly Significant less Engineering “Fewer” special components e.g. fewer stave flavors. Straw man: “Fixed Length Barrel”

Independent vs. Integrated Pixel Independent : Insertion “tube” as in ATLAS. Integrated : only “b-layer” attached to beam- pipe Independent Pixel: Schedule of the more complicated system is decoupled from the large area detector. Integrated Pixel: Less material? Services routed at lower h Better chance for common system One cooling system One Heat shield Straw-man: b-layer with the beam pipe, 2,3rd layer integrated with the Barrel.

Mechanical Support Mechanical support Stave Option “Drum” Option

“Stave” Concept The need for High degree of Multiplexing of power, readout etc. Lead to the concept of treating a set of modules in common. The mechanical support can be ATLAS like support (Drums) or mechanical Stave. For each group of modules: power, readout, grounding “fully contained” Service design needs to be “integrated” to the mechanical and layout. Some of these issues are independent if it is a real or “virtual” stave. At this stage we try to propose a level of multiplexing that will allow to get an estimate for services volume and routing. The decision on the mechanical concept will have to be discussed with the engineering team that will design the mechanical structure.

Drum vs. Stave Options Atlas Drum—Current Atlas Individual Silicon Modules are mounted on drum Stave approach to Atlas Upgrade; many modules on one long support structure (stave) Staves supported by endrings

ASSYMMETRICAL SENSORS POSITION Stave tilted to compensate for the Lorentz angle.

SYMMETRICAL SENSORS POSITION Stave tangential to the Radius.

Modularity – Installation Sequence Surface Assembly of the Barrel Assemble as much of the Barrel as possible. In this version we assume that we can assemble part of the disks already on the surface – this needs detail Eng. Studies. The installation sequence of ID in the pit. Step I: Moderator and services on IWV Step II: Barrel Surface assembly Step III: Barrel Services (cables, pipes) Step IV: Outer Discs Step V: Outer Discs services Step VI: b-layer + beam pipe

Surface Assembly – Step 1

Surface Assembly – Step 2

Surface Assembly – Step 3

Surface Assembly – Step 4

Surface Assembly – Step 5

Surface Assembly – Step 6

Surface Assembly – Step 7

Surface Assembly – Step 8

Ready to Transport to the Pit

Assembly in the pit– Step 1

Assembly in the pit– Step 2

Assembly in the pit– Step 3

Assembly in the pit– Step 4

Assembly in the pit– Step 5

Assembly in the pit– Step 6

Summary – Si Area