December 3, 20031Muon Integration Meeting B. Schmidt Introduction: The present architecture of the Muon System is based on the assumption that the maximal LVDS cable length is about 10m. The question has been raised (by our TC) whether this is really a hard limit. Motivation: M1 racks (in the tunnel under RICH 2) should preferably not move with M1. Concerns about the Electronic rack support structure for M2-M5. ->Only feasible if LVDS links can be longer than 10-12m LVDS cable length study

December 3, 20032Muon Integration Meeting B. Schmidt The findings: Werner and me compared the performance with 12m, 24m and 36m long LVDS links, with CARIOCA on one side and the LNF LVDS-ECL converter on the other. ->No significant difference in performance has been observed... ->Studies on the signal shape are still ongoing. We have to be careful with conclusions ! LVDS cable length study

December 3, 20033Muon Integration Meeting B. Schmidt ‘Balcony’ position (35-40m cable length) ‘Counting house’ position (>80m cable length) ‘Floor’ position (20-25m cable length)

December 3, 20034Muon Integration Meeting B. Schmidt OFF-detector electronic positions: Detector side (default): –Radiation tolerant electronics/power supplies required –Cable length well performance wise understood –Support structure complex (Material cost ~80kCHF) –Engineering study required –Cost for LVDS cables ~300kCHF (180k material, 120k work) -> Looks feasible Balcony position: –Radiation less critical –Cable length only very partially tested –Support structure simpler –Additional cost for cables ~450kCHF -> Cost is a problem LVDS cable length study

December 3, 20035Muon Integration Meeting B. Schmidt OFF-Detector electronics positions (ctd.): Counting house: –Radiation wise appealing –Problems with cable length are very likely... –Chicane not adopted for this amount of cables –Additional cost for cables >1 MCHF ->Excluded Floor position: –Slight advantages on radiation –Cable length partially tested –Space on the floor is a problem due to cryogenics ! –Additional cost for cables ~ 180kCHF ->Looks unfeasible LVDS cable length study

December 3, 20036Muon Integration Meeting B. Schmidt Removable platform LHC cryogenics platform Platform MF3 MF2 MF1 Rack position on cryogenics side Electronics Racks

December 3, 20037Muon Integration Meeting B. Schmidt Removable platform LHC cryogenics platform Platform MF3 MF2 MF1 Rack position on cryogenics side Electronics Racks Gas racks would have to be installed on the balconies -> additional piping cost

December 3, 20038Muon Integration Meeting B. Schmidt Conclusions: The default position remains to be the most feasible position for the OFF-Detector Electronics. Our findings should be tidied up and properly documented to avoid further discussions on the topic. LVDS cable length study