BelleII Detector
StatusKoji Hara (KEK IPNS)2018 Mar. 14
22nd KEKB Accelerator Review Committee

Belle II Detector
KL and muon detector (KLM):
Resistive Plate Counter (barrel)
Scintillator + WLSF + MPPC (end-caps)

EM Calorimeter (ECL):CsI(Tl), waveform sampling

Particle Identificationelectron(7GeV)Time-of-Propagation counter(barrel, TOP)
Prox. focusing Aerogel RICH (fwd, ARICH)

Beryllium beam pipe
2cm diameter

Vertex Detector (VXD)
2 layers DEPFET (PXD)
4 layers DSSD (SVD)

Central Drift Chamber (CDC)
He(50%):C2H6(50%), Small cells,
long lever arm, fast electronics

positron(4GeV)
General purpose 4p Detector
Improved PID, Vertex detector
High background tolerance

2Belle  BelleII Upgrade

SVD: 4 DSSD lyrs  DEPFET lyrs+ 4 DSSD lyrs
CDC: small cell, long lever arm
ACC+TOF  TOP+A-RICH
ECL: waveform sampling(Numbers are not final ones)
3
Feb.
24th,
2011
H.Nakayama(KEK)
KLM: RPC gScintillator +MPPC(end-caps)

3

KLM
Use glass resistive plate chamber (RPC) ofBelle KLM except for endcap and innermost
layers in Barrel endcap and innermost two layers inbarrel are replaced with scintillator + MPPC
to reduce deadtime

Scintillator Module

Scintillator modules have been installed in 2013-2014

ECL• Use Belle ECL CsI(Tl) crystals and PIN diodes• 30cm long CsI(Tl) (16.1X0)• 2x(2cm2) PIN diodes• 2 preamplifiers• Readout electronics has been upgraded• Shorter shaping time 0.5 μs• Waveform sampling Reduce background noise effect• Endcap Belle ECL have been installed again in2017-2018

TOPBarrel PID (TOF+ACC in Belle) is replacedwith TOP counter• TOF + Cherenkov Ring Image• Consists of quartz bar radiator and MCP
PMTsFirst module installed in Feb. 2016

MCP PMTs
Quartz bar radiator

TOP installation completed in May 2016

CDC
Belle II CDC
Belle CDC

CDC Installed in Oct. 2016

Upgraded to new CDC with smaller cell, longer
lever arms

BelleII Roll-in
BelleII moved to the beam lineon Apr. 11, 2017

Test beam setup and ring image

Aerogel radiator

ARICH

HAPD

Forward endcap PID is upgradedfrom threshold type Cherenkov
counter (ACC) to ring image
Cherenkov counter (ARICH)• Aerogel as radiator• Hybrid Avalanche Photo
Detector (HAPD)

Completed Aerogel and HAPD planes
being combined (2017 Aug.)

Final installation to BelleII
performed 2017 Sep.-2018 Jan.

ARICH Cooling Issue
Found heat extraction is not sufficient• temperature sensors:
46℃(right), 51℃(top)
45℃ (left), 37℃(bottom)• Temperature of electronics (“merger” FPGA) isin still acceptable range• Can be a potential problem for HAPD (underinvestigation)• Additional cooling bodies installed in Jan. 2018 not much improved
Additional cooling methods are being studied• add direct cooling by extracting ARICH andseparating endcap ECL during phase2-3transition

Merger FPGA core temperature

10Vertex and BeastII Detectors
in Phase 2

Phase2 vertex detectors are consists of partial PXD and SVD,
BeastII detectors for beam background characterization

PXD and SVD for PhaseII
1 sector of PXD and SVD are installed inthe direction where the largest beam
background is expected.
• 2 layers of PXD (4 half laddermodules)• 4 layers of SVD
Establish safe operation and confirm
beam background condition for phase312

BeastII Detectors• To study individual BG
components• Time evolution of BG• DAQ runs continuously
independent of BelleII GlobalDAQ(FE-I4 ATLAS Near Gamma Sensors)(sCintillation Light And Waveform Sensors)(Pixelated Ladder with Ultra-Low Material Embedding)13Radiation Monitoring

Phase2 Beam pipe and Diamond Sensors

Phase2  8 sCVD sensors
Phase3  8 + 12 sensors

Diamond sensors has been also tested in phase1
Readout system and abort generation system
has been installed Ready for the phase 2 first beam
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Phase2 VXD Installation• Phase2 VXD has been installed in Nov.
2017
• Also provided important test for
installation tools and procedure forphase3• Careful preparation based on theexperience of phase 2 is important• number of cables/pipes will be x1015

BelleII Global Commissioning
CDC hit and track in
GCR with B=1.5T

Global cosmic ray run with BelleII detector taken afterroll-in in 2017 July-Aug., Nov. (partial BelleII)

Global BelleII (phase2) cosmic ray run started in 2018 Feb.
• Already took some long (>hours) runs usable fordetector check and calibration• Tuning of central DAQ and each detector electronics
are being performed towards 30kHz data taking(maximum rate planned for BelleII phase3)
Pt resolution after Initial calibrationof CDC with GCR2017 data
Belle CDC only:~0.28𝑃𝑡 ⊕ 0.35 (%)
GCR2017 July:~0.13𝑃𝑡 ⊕ 0.31 (%)
Already better than Belle
CDC at the first step

“First Events” in 2018 GCRFirst cosmic ray track with PXD hitsFirst cosmic ray track with
Cherenkov Ring by ARICHFirst cosmic ray track with SVD hit

BelleII Phase2 detector ready for beam17

Phase 3 Vertex DetectorPXD+SVD cross section drawing
RL6=140mm
RL5=115mm
RL4=80mm
RL3=39mm

Layer-6SVD
Layer-5Layer-4
Layer-3collision point

PXD
RL1=14mm
RL2=22mm

935 mmAngular acceptance: 17°–150°

Layer-3

Phase3 SVD

Layer-4

Layer-5Layer-6
SVD Ladder production has almost finished.
• A few spare production remaining in 2018 March.
SVD assembly table has been built in the clean room at Tsukuba exp. hall B1.
• Mount ladders on support structure• Attach cooling pipes, install temperature sensors• Check of mounted ladders for cooling, electrical performance, position precision• etc.

Completed SVD +x half

SVD +x half picked up with combining jig• SVD is assembled in two half shells• Ladder mount started in 2017 Sep.
• First half (+x side) completed in2018 Jan.
• Complete second half by May• System test of SVD half shells May~
• Combined with beam pipe and PXDin Aug.
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Phase3 PXD

Ladder Production status (as of 2018 Feb.)
Strategy• Start with smaller batches of L1 modules(half ladder), then larger batches of L2• 50% contingency
L1• modules done
• 8 ladders assembled
1 b-grade ladder and 1 c-grade ladder
L2• all modules done up to SMD, testingongoing• Ladder assembly started in beg. of Feb.

Ladder Mount Preparation• Assembly tools and test stand being prepared• Half shell Assembly and Test at MPI&DESY (March – May)
 Deliver PXD half shells to KEK (June)21

Phase3 VXD Assembly At KEK• Phase3 Beampipe delivery in 2018 March• Solved Au peel-off problem in the firstproduction• VXD assembly setup for Phase3 being prepared• Basic test has been done with Phase2 setup

Phase3 VXD Assembly Table
being Prepared

SVD Half shell attachment
test using phase2 setup

Assembly schedule• Beampipe, shield monitor assembly Apr.
• System test of SVD/PXD half shells May-Aug.
• Integration of Beampipe, PXD and SVD Aug.
• System test of integrated PXD+SVD ~Sep.
• VXD installation to BelleII in Oct.-Nov.

Cable trays and hand crane used forPhase2  Phase 3 design in progress

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Summary• Belle Detector has been upgraded to BelleIIooo

Improved vertex and tracking detectors
Improved particle IDImproved background tolerance for condition in SuperKEKB• Phase2 BelleII Detector Installation has been completed and beingcommissionedooo

Global cosmic ray data taking with all detectors involved has started
Calibration and detailed check of detectors are starting
Phase2 BelleII detector and BeastII detectors are waiting for the first beam

Toward Phase3• Final vertex detectors are being assembled
ooooFirst half shell of SVD completed
PXD L1 ladders has been assembled
Assembly setup of full phase3 VXD is being prepared based on phase2 experience
Phase3 VXD will be ready for installation to BelleII in Nov. 2018

• ARICH cooling reinforcement is plannedo

Basically in parallel with VXD works23

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•••••••••

BelleII Detector Introduction
KLMECL
CDCTOP
Roll-in
ARICH
PhaseII SVD+PXD, BEASTII
PhaseIII SVD+PXD• TRG/DAQ• Global Cosmic Ray Test 1• Global Cosmic Ray Test 2• パス: Computing + Soft