Aug 13, 2007, WG-A meeting.
Present: Herve, Seryi, Sugimoto, Buesser, Damerell, Osborne, Oriunno, Tauchi, Markiewicz, Guarino, Parker, Chlachidze, Amann, Settles (+ possibly, other colleagues)
Alain Herve presented a scheme of IR hall with only one large shaft for detector assembly (see attached). It is positioned outside of the main footprint of the collider hall. A similar scheme is used now in 3 out of 4 LEP caverns. For ILC, in this scheme, there would be two shafts: 18m and 9m, both with stairs and elevators. Horizontal transport on air-pads is needed between the loading area onto the platforms. The single on-surface building is positioned in such a way, that the interference with the shaft construction, gantry crane movements, and trucks driving-in, is minimized.
Sliding from the floor at the bottom of the shaft onto the platform should be done when the platform is aligned vertically, while the horizontal gap (could be a cm) is covered by steel plates (the floor and the platform should be covered by steel plates permanently).
In discussion, in particular, Tom Markiewicz said that the experimental colleagues might be concerned about one shaft scheme because of possible interference and inequalities of A and B experiments.
Ron Settles doesn't completely agree with Tom's comment that the configuration could be disfavored by the experiments due to its asymmetry w.r.t. A and B. He thinks that for the two experiments, one should guarantee that they can be installed and serviced with about equal
ease, and that this should be carefully studied for the case of major repair, where one of the detectors has to have a significant intervention due to an accident.
Sugimoto-san presented updates on GLD: deformations due to magnetic field with improved boundary conditions; magnetic field modeling taking pacman iron into account; considerations of FD splitting after QD0.
Discussion and follow-up are needed for the sizes of QDO and QF1 cryostats, as in reality the drift between them should be larger. The real geometry may affect the support scheme.
To follow-on:
FD support scheme
Power & facilities needs from GLD, SiD (expected next week), LDC & 4th.