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)

12-OCT-2012 4 Gary Varner, TARGET6 Review @ SLAC

Belle II Physics Rates

KLM occupancy dominated by neutron Background hits

12-OCT-2012 5 Gary Varner, TARGET6 Review @ SLAC

Belle II Trigger Strategy

12-OCT-2012 6 Gary Varner, TARGET6 Review @ SLAC

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

12-OCT-2012 7 Gary Varner, TARGET6 Review @ SLAC

“Belle II Standard” DAQ Firmware • Belle2link for KLM

12-OCT-2012 8 Gary Varner, TARGET6 Review @ SLAC

Trigger Firmware Overview • Belle-like timing primitives for GDL (trigger)

New KLM trigger elements

12-OCT-2012 9 Gary Varner, TARGET6 Review @ SLAC

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

12-OCT-2012 10 Gary Varner, TARGET6 Review @ SLAC

Belle II Throughput

12-OCT-2012 11 Gary Varner, TARGET6 Review @ SLAC

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

12-OCT-2012 12 Gary Varner, TARGET6 Review @ SLAC

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

12-OCT-2012 13 Gary Varner, TARGET6 Review @ SLAC

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)

12-OCT-2012 14 Gary Varner, TARGET6 Review @ SLAC

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