1. ATLAS Upgrade ID Barrel: Services around ‘outer cylinder’ TJF 24.02.09 updated 12.03.09 According to the drawing ‘Preparation outer cylinder volume reservation’ (C.Bault 1.07.08), the inner surface of the outer cylinder is at R1033. Given this radius, it is possible to accommodate a continuous layer of cooling pipes from the SCT barrel with unmanifolded alternating exhaust and input pipes or grouped exhaust/input pipes in a single layer IF the number of staves is still no more than the ‘original’ 28, 36, 44, 56 and 72 ie 236 (total for one side, with each stave having one input and one output pipe. Although cooling pipes in this layout would not occupy more than 10mm in R, the structure/s that support them and protect them from being bashed during Installation (eg a SERVICES MODULE) would have to be substantial and probably take up an additional 20mm in R without including possible insulation. If power cables are used (rather than power tapes), it is possible that they could fit into another 10mm envelope in R, if evenly spaced and not bunched. The space envelope allowed for on the drawing between the inner surface of the ‘outer cylinder’ is 63mm (R1033 – R970). This is insufficient for the combination of services from barrel, pixel discs 1-3 and end-cap discs 4-8. IF SERVICES MODULES WERE USED, HOW WOULD THEY BE INSTALLED? 1

2. SERVICES MODULES containing cooling pipes, power and opto cables or Optofibres and DCS cables – how are they installed? Step A REAL ID BARREL with staves Outer cylinder Services jig: Barrel end + outer cylinder section. Services modules separate ends of services with connectors TJF ID (IT) barrel in cleanroom ID Barrel JIG in same cleanroom or adjacent, visible area 2

3. SERVICES MODULES – how are they installed? Step B REAL BARREL with staves Outer cylinder Services jig: Barrel end + outer cylinder section. Services modules After fitting on jig (pipe bending etc) and securing in services module shell, remove first module from jig……. 3

4. SERVICES MODULES – how are they installed? Step C REAL BARREL with staves Outer cylinder Services jig: Barrel end + outer cylinder section. Services modules then fit to outer cylinder and connect up cables and pipes, except for cables which may overlap those of the adjacent services module. 4

5. SERVICES MODULES – how are they installed? Step D REAL BARREL with staves Outer cylinder Services jig: Barrel end + outer cylinder section. new services module Next, fit a new services module adjacent to the second services module to be fitted on the real barrel….. 5

6. SERVICES MODULES – how are they installed? Step E REAL BARREL with staves Outer cylinder Services jig: Barrel end + outer cylinder section. new services module Make sure the services from adjacent modules fit, then remove the module to be installed on the real barrel and fit. 6

7. IS THIS PROCESS USING SERVICES MODULES FEASIBLE? Each services module contains a few of each type of services, some rigid and formed such as cooling pipes and some very fragile such as readout micro cables or fibres. The filled services module would be an unwieldy and heavy object to move about with metal edges a hazard to thin cables. It could also bend and twist over its length. There would be services sets with ends of different lengths – very difficult to handle, first when assembling on a jig and then when installing and connecting, even if only transporting from one part of the cleanroom to another. Some services would have to be embedded under others when packing the services module so that inspection would be difficult if such a cable or pipe failed during testing in situ after connection. Long pipe lengths inside the Services Module and extending to end barrel connections would certainly place stress on the barrel staves and would thus require substantial bracketry on the barrel end to take the stress off the stave structure. Power cables inside sleeving would place even more stress on barrel end connectors and the stave. How strong does the stave with integral connectors have to be at the barrel end? Very! As we observed on the SCT barrel, a ‘spider’ of 5 or 6 cooling exhaust pipes, even with bellows to allow flexibility, was difficult to connect up to the barrel. In the end bellows could not be used and each exhaust pipe was connected up separately as were the input pipes. A 32 way layout in phi would mean that Services Modules would take up more space if they are in the form of channels or boxes with ‘lids’. 7

8. WHAT TO DO NEXT? Assume all new services from ID out to PP2 but probably best to also assume same or very similar position in phi to old services ie based around 45 degs for cooling with readout either side of this and power cables spaced approx. evenly in quadrants allowing space for cooling and (im)possibly big opto boards. Assume a SINGLE baseline LAYOUT for ID which may well change many times! A 32 way layout still means there would be more than 7 staves served by one Services Module which is a lot, probably 6 too many! POSSIBLE SOLUTIONS: Connect up each type of service separately, finishing and testing one type before starting another. Bunch small sets of the same type which could be packed in a small ‘module’ or channel with others. Cooling could be bunched but not packed and could occupy dedicated space envelopes without intertwining with cables. CONCLUSION: Probably unfeasible as an ‘all services module’ given only limited access: handling and connecting a bunch of services all of one type is difficult enough without combining several types. Cooling pipes with connectors would be very difficult to control when in a mixed bunch and would obstruct access to other connectors. The ID barrel would have to be rotated for each SM installation. 8

9. MAPPING for BARREL services based on the following layout for ONE end: ACTIVE TOTAL COOLING COOLING POWER READOUT DCS LAYER R STAVES OUTPUT INPUT CABLES ORDER R 380 28 28 28 28 x 2 28 x 2 bunch 5th R 490 36 36 36 36 x 2 36 x2 bunch 4th R 600 R 750 56 56 56 56 x 2 56 x 2 bunch 2nd R 950 72 72 72 72 x 2 72 x 2 bunch 1st 44 44 44 44 x 2 44 x 2 bunch 3rd Using the only known ‘baseline’ dimensions and stave numbers 9

10. MAPPING for BARREL services based on the following layout for ONE end: ONE QUADRANT eg side A, QUADRANT A1 with cooling centred on 45 degs. POWER CABLES: one stave, (half length of barrel) in one sleeved bunch. 59 sleeved bunches from one quadrant, going to 20 ‘power services modules’ arranged in 4 sets of 5 either side of COOLING centred on 45 degs and READOUT centred on 22.5 degs READOUT CABLES or FIBRES: one stave, (half length of barrel) in one sleeved bunch. 59 sleeved bunches from one quadrant, going to 4 ‘R/O services modules’ arranged in 2 sets of 30 either side of COOLING centres on 22.5 degs. NB this is assuming ‘opto’ board is mounted somewhere on the stave, rather than being remote from the detector. IF remote then distribution of cables will need to be spaced out rather than bunched. OUTPUT COOLING: one stave, (half length of barrel), one pipe with no manifolding. ie 59 pipes directed to 2 layered bunch centred at 45 degs INPUT COOLING: one stave, (half length of barrel), one pipe with no manifolding. ie 59 pipes directed to 2 layered bunch centred at 45 degs either side of output cooling 10

11. POWER and DCS cables READOUT cables or fibres COOLING output COOLING input spare space reserved for rails etc Services fan-in to main pathways from area of octant, all layers via the shortest possible route BARREL MAPPING 11