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Geometry: GE1/1 vs ME1/1. GEM 1/1 Geometry. GEM Super- chambers. BeamLine. I.P. The distance from the beamline to the axis of the pivoting parts of the chambers is 1274mm in “Y” direction. T he definition of X, Y, Z directions and phi, eta angles. GE1/1 Detector Layout.
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GEM Super-chambers BeamLine
I.P. The distance from the beamline to the axis of the pivoting parts of the chambers is 1274mm in “Y” direction.
GE1/1 Proto2 – Readout Board 128 channels per VFAT connector 24VFAT FEBs 3072 channels 384strips for each eta partition Strip’s pitch 0.8mm Strip’s pitch 0.4mm
152.68 mm 151.68 mm 123.76 mm 122.76 mm 103.8 mm 103.8 mm 101.1 mm 102.12 mm 393.05 mm 393.05 mm 393.05 mm 393.05 mm 366.51 mm 366.17 mm 344.51 mm 344.33 mm 322.86 mm 322.51 mm 304.34 mm 304.17 mm 286.01 mm 285.83 mm 268.14 mm 267.96 mm 393.22 mm 419.934 mm 250.1 mm 970.63 mm
ME1 Rings And Chambers • ME1 stationhas 3 physical rings • Each ring has 36 chambers • Phi position of chamber #n :phi(n) = (n-1)*10o • Links: • Note on CSC numbering conventions CMS IN-2007/024 • ME1/1 chambers details twiki ME1/1 ME1/2 ME1/3
ME1/1 Chamber Details ME1/1 = ME1/a + ME1/b Continuous wire groups coverage 48 wiregroups at 29o inclination angle WG #11-16 cross the border between 1/a & 1/b Separate sets of strips in 1/a & 1/b 1/b has 64 strips read out by 4 CFEBs (16 strips/CFEB) Odd & even chambers overlap by ~5 strips 1/a has 48 strips Currently ganged in sets of 3 and read out by a single CFEB After upgrade will be read our by 3 digital CFEBs Odd & even chambers overlap by ~3 strips Sensitive volume dimensions are from NOTE-2008/026 Etas we calculated at average z between odd & even chambers ME1/1 487 h=1.55 ME1/b 1505 h=2.10 ME1/a h=2.44 201
ME1/1 Ring & Layers Details in r-z view Odd & Even chambers are staggered in Z Distance between odd & even chamber centers in z is ~293mm Each chamber has 6 layers in z Layer is 7 mm thick Z-spacing between two layer centers is 22 mm ~110 mm between 1st and 6th layers Whole chamber thickness is 147 mm r 110 2565 22 Towards IP η=1.62 η=1.56 293 147 1500 Towards IP η=2.07 η=2.13 z 1060 Towards IP 5820 5875 6054 6113 6168 η=2.40 η=2.47
ME1/1 and GE1/1: two chambers Odd numbered CSC chambers , located farther away from IP then even ones, are also at much larger distance from their companion GEM chambers
CSC chambers vs GEM: r-z view All ME1/b eta range for odd numbered chambers (farther away from IP) is covered by GEMs But the distance to GEMs would make matching less precise Would TMB receive signal from left and right GEMs? Even numbered chambers don’t cover in eta the top of ME1/b, but do cover a bit of ME1/a top GEMs are close, so the precision of matching should be better Would need different conversion for odd and even chambers
Strips vs. GEM readouts4CSC phi-coverage Phi-coverage of chambers from their dimensions and known radial positions: Each one out of 36 ME1/1 chambers: 10.945 deg Each GE11 chamber: 10.15 deg Phi-coverage per trigger readout: ME1/b (64 strips): ~ 0.171 deg/strip Most of ME1/b would be covered by GE1/1 ME1/a (48 strips): ~ 0.228 deg/strip Only top fraction of ME1/a would be covered by GE1/1 GE1/1 (if each eta partition has 16*3 readouts for CSC with grouping of 8 GEM channels into a single readout4CSC): ~ 0.211 deg/readout4CSC It’s somewhat close to ME1/a strip phi-coverage Ideal grouping for matching ME1/b strip phi size would be 6.5 gem strips – not feasible! GE1/1 with 16-grouping of strips: ~ 0.423 deg/readout4CSC Which is ~2.5 ME1/b strips Note: the phi granularity of CSC trigger is half-strips
Wiregroup vs. GEM readouts4CSC coverage Things are more complex with wiregroups, as they are slanted at 29deg Naively, from 1505mm chamber length with 48 WG, we get ~ 31 mm/WG Taking the 29deg slant into account, single WG covers in local y: At the top of ME1/a ~ 250 mm At the bottom of ME1/a ~ 160 mm GE1/1 eta partition sizes: At the top ~ 153 mm At the bottom ~ 102 mm