Possible SLHC Modifications to Clock Distribution Chris Tully, Dan Marlow Princeton Madison, Wisconsin February 13, 2003 Current SLB Clock Distribution Current SLB Clock Distribution 80 MHz TrigPrim Generation 80 MHz TrigPrim Generation Improvements for Forward Tagging Improvements for Forward Tagging Parallel MET/SET and Jet Finding Parallel MET/SET and Jet Finding

7/11/03HCAL TTC FanoutC.Tully 2 Mark I Clock and BC0 Fanout 16 Channel TTC Fanout (now increased to 18) Four Pairs (LVPECL): 80 MHz 40 MHz BCO Enc. TTC

7/11/03HCAL TTC FanoutC.Tully 3 Signal Routing FPGAFPGA Choice of BC0 Both w/Delay Choice of BC0 Both w/Delay Choice of 40MHz Both Opt. Cleaned Choice of 40MHz Both Opt. Cleaned Source of 80MHz Optional Optional TTC Encoded

7/11/03HCAL TTC FanoutC.Tully 4 Phase Alignment Current Regional Calorimeter Specification Requires all ECAL and HCAL Inputs arriving within 6ns If 80 MHz operation requires phase alignment to 3ns, then the clock and BC0 signals need cleaner paths.

7/11/03HCAL TTC FanoutC.Tully 5 HCAL TPG – Current 40MHz Scheme SLB TPG40 SLB TPGBC0 TTC TTCrx Crate80 Serial Optical Data Ref Clk Deserializers (8) 20 Recovered Clk TPG Path SYS40 Clk TTC Broadcast Async Fifo PLL TTC40 x2 XILINX LC Fiber Data Princeton Fanout Card (1/VME crate) SYS80 Clk Princeton Fanout Card (GLOBAL) HCALHCAL

7/11/03HCAL TTC FanoutC.Tully 6 BXID and Energy Estimates “Peak Detection” methods which operate on 40MHz data will not ID the peak to better than 25ns. For the HB/HE pulse shape, an Energy-Weighted Pulse Time will ID to better than 12.5ns ns Energy Time (25ns Steps) Energy can be rescaled or have a separate set of weights.

7/11/03HCAL TTC FanoutC.Tully 7 HF Detector

7/11/03HCAL TTC FanoutC.Tully 8 HF detector HAD (143 cm) EM (165 cm) 5mm To cope with high radiation levels (>1 Grad accumulated in 10 years) the active part is Quartz fibers: the energy measured through the Cerenkov light generated by shower particles. Iron calorimeter Covers 5 >  > 3 Total of 1728 towers, i.e. 2 x 432 towers for EM and HAD  x  segmentation (0.175 x 0.175)

7/11/03HCAL TTC FanoutC.Tully 9 Main Physics goal of HF 6 fermion final state! W p p fwd q (in HF+) q q l,q l,q W fwd q (in HF-) HF range HF range Tagging High energy forward jets: for ‘physics’ analysis P t (~20 GeV/c) the jet energies concerned are ~200 GeV at the outer edge of the detector and 1 TeV at the inner edge H Must be isolated in  R>0.4 (Check 2x3 Neighbors)

7/11/03HCAL TTC FanoutC.Tully 10 Parallel MET/SET and Jet Finding Currently Electron/Photon Finding “the Work Horse of the Regional Calorimeter Trigger” Shares Resources with MET/SET Summing This pushes the limits of the system and creates a complicated and dense backplane architecture. If the synchroniziation where done first, then fine and course grain tasks could be split to separate crates. Receivers/SyncReceivers/Sync Electron/Photon(/Tau?)FindingElectron/Photon(/Tau?)Finding MET/SET Jet finding (using isol.) MET/SET Partial sums (fewer links) Towers

7/11/03HCAL TTC FanoutC.Tully 11 What Can Princeton Do? Timing Distribution Improvements for 80 MHz Trigger Operation Help in Design/R&D of SLHC Trigger System. 2(3) Physicists: D. Marlow, C. Tully, (J. Mans) 2 Layout/Board Design Techs: S. Chidzik, Bert 2/3 Mech/Cable Engineers