Belle II KLM Readout Upgrade - University of Hawaiʻi
Transcript of Belle II KLM Readout Upgrade - University of Hawaiʻi
Belle II
KLM Readout Upgrade
Gary Varner University of Hawai’i
12-OCT-2012
electrons (7GeV)
positrons (4GeV)
KL and muon (KLM) detector: Resistive Plate Counter (barrel) Scintillator + WLSF + MPPC (end-caps)
Particle Identification Time-of-Propagation counter (barrel) Prox. focusing Aerogel RICH (fwd)
Central Drift Chamber He(50%):C2H6(50%), Small cells, long lever arm, fast electronics
EM Calorimeter: CsI(Tl), waveform sampling (barrel) Pure CsI + waveform sampling (end-caps)
Vertex Detector 2 layers DEPFET + 4 layers DSSD
Beryllium beam pipe 2cm diameter
Upgrading the Detector Belle to Belle II
2
Trigger and Data Acquisition
KLM upgrade
Requirements to keep (and improve) KLM performance
Chosen option
RPC-based KLM demonstrated nice performance at Belle (efficiency endcap > 90%, barrel ~ 99%, stable operation, low bg)
With SuperKEKB luminosity because of large RPC dead time endcap KLM efficiency drops to 0; barrel KLM ~ 50% in the innermost layer; quick recover to 100% with increasing # of layer
Low dead time: <<µ sec for a typical channel (strip) area 1000 cm2
Large geometrical acceptance: > 95% High detection efficiency: ~99% for MIP Low bg (neutron bg + electronic noise)
Scintillator based detector with WLS readout Fast photodector: Si photo diode in Geiger mode (SiPM - Hamamatsu MPPC) Independent operation of x-y layers
(~20,000 channels to read out: 16.8k endcap, remainder barrel layers 1,2)
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Belle II Physics Rates
KLM occupancy dominated by neutron Background hits
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Belle II Trigger Strategy
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Firmware Overview • Operate within Belle-II Trigger/DAQ
environment • >= 30kHz L1 • Gbps fiber Tx/Rx • COPPER backend • Muon trigger • Super-KEKB
clock/timing SuperKEKB RF clock
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“Belle II Standard” DAQ Firmware • Belle2link for KLM
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Trigger Firmware Overview • Belle-like timing primitives for GDL (trigger)
New KLM trigger elements
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KLM Trigger Firmware (2) • Merge streams to reduce # of links • Implement algorithms in a common trigger
module (UT3) • Trigger algorithm finds 2D track(s) in each
projection
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Belle II Throughput
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FTSW for programming/ timing/trigger
20k channels 1.25k 16-channel
Waveform sampling (TARGET) ASICs
112+32 SRM
112+32 DAQ fiber transceivers
36 FINESSE 9 COPPER
Trigger is common with RPC/barrel : Use a common merge board
Si-KLM Architecture Overview
1.4k 15-channel Pre-amps
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FTSW for programming/ timing/trigger
~20k channels No ASIC Required
208 SRM
16 DAQ fiber transceivers
8 FINESSE 2 COPPER
Trigger is common with RPC/barrel : Use a common merge board
KLM RPC Readout ~ few ns timing, 3D muon trigger
13 SRM/VME crate 16 crates
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Firmware Development Task-sharing • SRM (MB v.2) firmware (KEK/ITEP; Hawaii)
– TARGET4 initial pre-amp testing – Operation of eKLM quadrant at KEK
• (pre-)Production TARGET6 ASIC (Hawaii/SLAC*) • TARGET_DAC daughtercard (Hawaii) • 9U VME version of SRM (Hawaii) • Belle2Link protocol conversion (Hawaii/PNNL/IU*) • Trigger/fiber merge board (Indiana) • Trigger firmware (Virginia Tech)
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