IR Eng. workshop, WG-A


Meeting of a working group in preparation to the ILC Interaction Region Engineering Design Workshop, IRENG07.

WG-A, group meeting.

Start time:
06:00 San Francisco
08:00 Chicago
09:00 New York
14:00 London
15:00 Geneva
22:00 Tokyo

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    • 6:00 AM 6:25 AM
      Utilities and services needs on the example of CMS 25m
      Speaker: Andrea Gaddi (CERN)
    • 6:25 AM 6:50 AM
      Compact GLD, Endcap design, mitigation of deformations due to magnetic field 25m
      Speaker: Dr Yasuhiro Sugimoto (KEK)
    • 6:50 AM 7:15 AM
      CMS endcap design, magnetic field mitigations 25m
      Speaker: Farshid Feyzi (High Energy Physics - Department of Physics - University of Wisc)
    • 7:15 AM 7:35 AM
      IR vacuum system arrangements in CMS -- ion pumps plus NEG 20m
      Speaker: Adriana Rossi (CERN)
    • 7:35 AM 8:00 AM
      Proposal for experiment (LDC) in the hall and possible surface arrangement of surface buildings 25m
      Speaker: Alain Herve (CERN)
    • 8:00 AM 8:20 AM
      SiD sceletone deformation study 20m
      Speaker: John Amann (SLAC)
    • 8:20 AM 8:25 AM
      Minutes of the meeting 5m
      WG-A, August 6, 2007 Present: Herve, Gaddi, Seryi, Kozanecki, Parker, Damerell, Clerc, Sanuki, Sugimoto, Meyners, Malyshev, Tauchi, Keller, Markiewicz, Krempetz, Feyzi, Pei, Yamamoto, Oriunno, Amann, Rossi (+possibly other colleagues). Andrea Gaddi presented utilities and services needs on the example of CMS. See slides for details. Several particular points maybe not mentioned on slides: UPS system is up to 2MW. The diesel (750kW) system has 1/2 minute start-up time. For ECAL, there is ~50% of losses in DC-DC converters and distribution system. ECAL require 16deg C +-0.05 deg C, this is one of the reason to have independent cooling loop. Another reason to have several loops is use of different materials: Al and Copper, which should not be combined in a single cooling loop. The temperature stratification is quite small in CMS hall -- and this is important; larger stratification would not be good for detector calibration. Sugimoto-san presented compact GLD: GLGc, see slides. Questions were asked: Chris Damerell: How the support tube is supported and what is its thickness: Answer: 10cm. FCAL also supported by this tube. Yamaoka-san calculated the deformations (numbers?) Comments: What happens if FD is disconnected after QD0? Is it possible to include pacman iron in magnetic field calculation? Alain: constraint at outer radius R=6.9m is not realistic, need to let endcap rotate around R=4.1m. The big question is also how to access chambers. Farshid: constraint to have ~70% of GLDc endcap fixed would result in under-estimation of total deformation. Alain presented a proposal for experiment (LDC) in the hall and possible surface arrangement of surface, see slides. Question was asked about shielding used for commissioning. A: it can be removed after use to the surface. Adriana Rossi discussed IR vacuum system arrangements in CMS -- ion pumps plus NEG, see slides. Some additional comments: in LHC all warm chambers covered with NEGs. Thickness of heating equipment is 1cm or 0.5cm if minimized. Neg coating is ~2 microns. Adriana and Malyshev discussed that it is better to have continuous coating without interruptions (e.g. in IP). Witold suggested that it is important to clarify requirement of IR vacuum in terms of possible contamination of the cold bore FD region. The absence of valves between FD and IR on the IR end is a complication from vacuum point of view. Temperature of baking in LHC: min 150deg C, up to 220 deg C. Malyshev: SS usually at 250 deg C, while Neg coated surface baked to 150 deg C would have similar outgassing properties. Brett: do not anticipate baking cold FD parts, and no valve between FD and IP. Witold: should a prototype system be tested in a lab in terms of vacuum performance? Farshid presented drawings and photos of CMS endcaps and discussed the design. Draft slides will be posted later. Endcaps were not split. If they would be, one would need huge forces to hold them together. In deformation analysis the constraint was at R~4m, outer end was free. If the outer end would be constraint, that would require applying very large force on the barrel, and could not do that. 24 aluminum octagonal posts at r~4m touch barrel and resist the force. In calculation of deformations the outer R end moved out by 5-6mm, and inner R mover in by 10-12mm. Described spherical sockets with hydraulic clamping jacks that connect endcaps. Modeling is done separately, to address particular questions, e.g. to calculate the stress in a welding zone, or in a bolt zone, etc. John Amann presented first results on SLD-like SiD deformation due to uneven lifting. There are number of questions how this calculation will change if the detector would be compatible with surface assembly, etc. Actions: Follow-up with CFS colleagues on CMS & ILC services, power and facility requirements, and with surface buildings and collider hall. Detector concepts -- specify services, power and facility needs considering CMS case as a starting point. Vacuum system -- suggest a straw-man IR vacuum system at one of the next WG-B meeting. GLD -- make calculation of distortions due to magnetic field with different constraints: use only constraint at about 4m, while leaving the outer radius free to rotate. GLD -- elaborate what happen if the FD split is after QD0, as assumed presently. GLD -- include pacman iron into calculation of magnetic field Study CMS endcap design (Farshid will provide more information)