WG-A, Aug 20, 2007
Present:
Sugimoto, Sanuki, Markiewicz, Herve, Parker, Settles, Seryi, Damerell, Krempetz, Buesser, Tauchi, Oriunno, Guram, Keller, Morse, Amann, Kozanecki, Breidenbach (+ possibly other colleagues)
Sugimoto-san have shown updates on GLDc. See slides for details.
Marty presented SiD services, see slides.
Note that the whole cross-sectional area of SiD services fits in 0.1m**2
(not mentioned on slides: dT for chilled water for electronics is 1-2 degree C, and about 15 deg C for LCW for solenoid leads)
Comment: PS for solenoid is on platform and DC cables are fixed, do not need to be flexible.
Alain Herve presented continuation of IR hall layouts, single shaft version and version with two large shafts offset from the hall center.
Shown also a solution to avoid interference of cover shaft with lift in the shaft.
Q: if TPC extraction needed, could detector move to the right. A: yes, on a platform, if, e.g., airp-ads are used for detector parts.
What about major problem like extraction detector solenoid? Detector could be rotated 90 deg and hall length used for this extraction (which will be done with cantilevered support).
TPC should be extractable in garage position.
Q: can we have notch on the hall wall to support the crane? A: it is very difficult, at least in the CERN geology.
Q: if in GLD the QD0 would be supported from the door, how would this affect the length of the shielding and the hall width?
John Amann presented updates on the platform developments, see slides.
Discussion about shims under platform that could be used for fine adjustment of height and compensation of settlement. (Example-- around 2mm of motion over 10 years in Atlas cavern, and actually very difficult to measure).
Discussion about GLDc pacman shielding where there is assumption that a person could walk in into the shielding. This may contradict to self-shielding, since now the offset for the hole in the pacman for cryogenics should be mush bigger. Brett thinks that access to QD0 area from inside of the tunnel is not needed, and service can be done with pacman opened.
Urgent action item: consider a mixed scheme, with one detector supporting QD0 from the door, as present SiD, and another is supporting it with the support tube, as present GLD, and understand if it work, or if we have to use non-mixed scheme.
