Mini-Trigger/DAQ workshop,OCU ECL Trigger overview ByungGu Cheon (SKKU) Outline ECL calorimeter ECL trigger scheme & performance Recent trigger upgrade status ECL trigger system @ 1035 super-KEKB Summary 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Belle ECL (Electromagnetic Calorimeter) 8736 CsI(Tl) crystals g & e energy and position measurement Trigger info. generation : powerful tool to suppress BG events. 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU ECL Trigger Trigger concept/requirement Suppress beam-BG and cosmic events Separate physics events from Bhabha/gg Fast trigger decision < 1.85 ms Good timing resolution Trigger condition Trigger Cell (4x4 matrix) : ETC > 100MeV Energy trigger : Total energy sum > 1GeV Isolated cluster counting trigger : # of clusters > 3 Bhabha & cosmic-veto triggers 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Trigger Cell Map Analog cell 576 Trigger cells ICN 136 Analog cells  ETOT & Bhabha/gg Physics trigger region (Etot / ICN) 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Bhabha/gg trigger Using Back-to-Back condition of each bhabha type depending on qLAB angle with high energy threshold. Bhabha type Threshold (GeV) Type 1 5.0 Type 2 5.5 Type 3 Type 4 Type 5 Type 6 Type 7 Type 8 Type 9 Type 10 Type 11 3.0 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Cosmic veto trigger Using naive event topology of hadronic process events against cosmic ray and beam BG topologies. energy trigger effi. r-f Plane in Barrel Region B A B A IR IR C D C D 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Trigger Scheme Isolated cluster counting trigger Energy trigger and Bhabha trigger 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Trigger efficiency Energy trigger ICN trigger Bhaha trigger e ~ 97% e ~ 95% e ~ 99% 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Trigger rate tendency ETOT>0.5GeV ETOT>1.0GeV ETOT>3.0GeV Trigger rate : 900Hz, 400Hz, 250Hz @ 7x1033 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Trigger rate tendency ICN bit0 ICN bit1 trigger rates @ 7x1033 : 10KHz, 1.3KHz, 55Hz, 17Hz ICN bit2 ICN bit3 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Trigger rate tendency trigger rate @ 7x1033 : 350Hz, 100Hz, 10KHz, 14KHz Bhabha Pre-Bhabha Cosmic Timing 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Motivation for new trigger system Weakness of Bhabha trigger for e+e-  gX event selection Separate Bhabha and gg events in the trigger level Expect much stable Bhabha/gg tagging than current system Using f directional Back-to-Back condition Tag of eegX Matching with track trigger bits MC simulation study Bhabha trigger efficiency : 99% gX trigger efficiency : 37%  72% 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Electronics flow chart New trigger system 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Hardware in new system BTL TPSD CVC ETM (32) (4) CCM & EBM STM AAA Newly added chain GDL 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Bhabha/gg tagging r-z plane r-f plane 5 1 Back to back for q Back to back for f 8 overlapped sectors Bhabha = q & f !! For f, 8 overlapped signals @ r-f plane. 4 back to back combined signals. 4 back to back combined signals with different threshold For q, 16 overlapped signals @ r-z plane. 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Bhabha, gg and gX Back-to-Back r-f plane ECL 1 5 2 6 3 7 4 8 5 1 CDC 1 5 2 6 3 7 4 8 8 overlapped sectors Bhabha trigger : ECL(1&5) & CDC(1&5) gg trigger : ECL(1&5) & CDC(0&0) Generate triggers by matching with track information ! gX trigger : ECL(1)+CDC(0) & Bhabha/gg veto 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Logic simulation study 5 1 & & TRK 1 & 5 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Threshold calibration Threshold table for r-z Threshold for r-f ( GeV ) D 1 5 3GeV 7GeV Type 1 2 3 4 5 6 7 8 9 10 11 FWD 4.5 ---- BWD 3.5 Threshold calculation ON ON+OFF 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Threshold calibration Setting of threshold for all channels 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Expected L1 trigger rates @ 1035 super-KEKB Trigger bit Rate @ 1035 ETOT>0.5GeV 6.5K ETOT>1.0GeV 3.4K ETOT>3.0GeV 2.5K ICN bit-0 18.0K ICN bit-1 5.0K ICN bit-2 0.5K ICN bit-3 0.2K Bhabha Pre-Bhabha 1.5K Cosmic 38.0K CsI timing 110.0K Estimated with current trigger performance Depend on super-KEKB beam condition Some flexibility: ETC & physics trigger region Optimize btw trig efficiecny and trig rates TC pulse width : 1ms TC occupancy < 10KHz @ 1035 Current L1 trigger system can be kept. 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

L2/L3 trigger @ 1035 super-KEKB It’s rather difficult to make concrete plan to prepare L2/L3 triggers before Trigger+DAQ readout scheme is finalized. slow preAmp Shaper Flash-ADC L2/L3 PC farm Software triggers for ECL ET balance ECL/CDC matching TC hitmap pattern Total Energy Cluster finding logic fast ECL L1 trigger GDL CDC L1 trigger TOP L1 trigger KLM L1 trigger 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

CsI(Tl) Barrel + pure-CsI Endcap Current trigger system should be modified to accommodate both outputs in the trigger level. Simple(?) concept to modify endcap electronics : preAmp  fast shaper  STM for Barrel region preAmp  new fast shaper  STM for endcap region pulse height correction + active timing delay potential problem of trigger timing resolution Crystal  g/cm3 X0 cm em nm Nph/MeV decay nsec CsI(Tl) 4.51 1.86 550 52000 1000 CsI 305/400 5000 10/1000 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU

Mini-Trigger/DAQ workshop,OCU Summary Current ECL trigger works well and new Bhabha trigger system is in progress. We expect the new system to be implemented before KEKB winter shutdown. Current ECL trigger system can be used at 1035 super-KEKB. Trigger electronics R&D work is necessary if pure-CsI is chosen to endcap calorimeter. 2002.10.28-29 Mini-Trigger/DAQ workshop,OCU