40 likes | 151 Views
Questions raised after our last meeting (26 August 2010): do you agree to define two values of unit cost for tungsten, one for "HCAL grade", another for "ECAL grade" ? Markus: OK if ECAL cost has a relative effect >5% ( ie if share between them is could change in a non-significant way )
E N D
Questions raised after our last meeting (26 August 2010): do you agree to define two values of unit cost for tungsten, one for "HCAL grade", another for "ECAL grade" ? Markus: OK if ECAL cost has a relative effect >5% (ie if share between them is could change in a non-significant way) Marty: Probably possible in principle. If we go to a vendor and ask for estimates for the two classes of thicknesses and tolerances, at least the delta cost should be useful. And of course, the delta cost can be compared across different vendors. A complication is that the “ECal” spec for SiD and ILD may be different – thicknesses, plate size, and tolerance are all issues.
do you agree to define two values of unit cost for steel, one for HCAL, another for the magnet yoke ? Markus: OK same reasoning Marty: For the steel, I don’t see the point. The magnet steel number is a sweeping average over actual material costs from the mill, plus machining, finishing, trial assembly, painting, and perhaps delivery. For the HCal, I see it as a different material – and we might want to consider brass or copper! Here, it would begin with a mill cost, and any machining is an extra item in the WBS. Catherine: Based on industrial offers for CMS, which were scaled to LDC, the materials costs were estimated to be Coil : SS304, 12€/kg; Yoke: SS 3, 6€/kg
is it reasonable to attempt to define a unit cost of "electronics per channel" ? Markus: You mean irrespective of the type of detector? I doubt we can get a meaningful average Marty: I believe it is not reasonable to define a cost of electronics per channel. For our e+e- environment, there is probably no trigger, and highly integrated electronics. For SiD, the tracker and ECal (and perhaps the HCal) have 1024 channels per chip. The costs are believed dominated by connections, and the cost of the chip is noticeable but small compared to bumping and cables. It might make more sense to define a cost per chip and associated cabling and connections.