The SuperKEKB ProjectChristoph Schwanda, Vienna
representing the Super KEKB collaboration
SuperB WorkshopLAL, Orsay,February 15-18, 2009
3
~1 km in diameter
Mt. Tsukuba
KEKB
Belle
8 GeV electrons on3.5 GeV positrons
• Ecm = 10.58 GeV ( Y(4S) resonance )
• Lpeak = 1.712 x 1034 cm-2s-1 (Nov-15, 2006)
4
Luminosity history
Belle will have ~1/ab (~1 billion BB events)by the end of data taking in March 2010
5
From KEKB to SuperKEKB
Stored currents:1.7 / 1.4 A (e+ / e- KEKB)
9.4 / 4.1 A (SuperKEKB)
Beam-beam parameter:0.059 (KEKB)
>0.24 (SuperKEKB)
Vertical at IP:6.5 / 5.9 mm (LER/HER KEKB)
3.0 / 3.0 mm (SuperKEKB)
Increase luminosity from 1.7x1034 cm-2s-1 (KEKB)
to 8x1035 cm-2s-1 (SuperKEKB)
7
15
179
40
31
178
Cost(oku-yen M$)
x2-4Higher beam-beam parameterCrab cavities
x3High currentMore RF and
cooling systems
If not x0.75Reduce emittance of
injected e+ beame+ damping ring
x2Smaller *New IR
x1.5Enable high current
reduce electron cloudNew beam pipes
LuminosityEffect
preliminary
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The Belle detector
μ / KL detection
14/15 lyr. RPC+Fe
CsI(Tl) 16X
0
Si vtx. det. 3(4) lyr. DSSD
SC solenoid 1.5T
8 GeV e
3.5 GeV e+
Aerogel Cherenkov cnt. n=1.015~1.030
Central Drift Chamber
small cell +He/C2H5
TOF counter
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From Belle to sBelle
• (At least) maintain the current Belleperformance in harsh backgroundenvironment
• Baseline design
– SuperKEKB Letter of Intent (LoI)KEK Report 2004-4
– sBelle Design Study ReportKEK Report 2008-7
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Particle ID:ring imaging Cherenkov devices(TOP in the barrel, ARICH in the forward)
Baseline design
Silicon:2 lyrs pixel,4 lyrs DSSD
Drift chamber:smaller cell size
Em. calorimeter:wave form samplingpure CsI (endcaps)
Muons, neutrals:scintillator strips (endcaps)
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DEPFET pixel layers
• Build by collaboration around MPIMunich (http://www.depfet.org/)
• 2 pixel layers close to beam pipe(r > 1.3cm)
• Pixel size 50 μm x 75 μm
• Fully depleted sensitive volume
• Row-wise readout
• Sensor thinning (50 μm)S/N 20-40 @ 50 μm
• Radiation hard
DEpleted P-channel FET
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Silicon strip layers
• Front-end chip: APV25(originally developed for CMS)
• 6 consecutive time samples forhit time reconstruction
• Chip-on-sensor for outer layers(origami module with thinnedAPV25)
• DSSD manufacturer? zylon rib
APV25 cooling pipe
4-layer kapton hybrid
integrated fanout(or: second metal)
DSSD
single-layer flex wrapped to p-side
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TOP counter for barrel PID
• Cherenkov photons reflected inside quartz radiator
• Cherenkov image reconstructed from one coordinateand precise timing
• Successful test of realistic prototype in June 2009
IP
Forward Backward
Focus mirror(sphere, r=5000)
32.8o~123.5o
47.8o
R=1180z=1830 z=1070 z=-780
5mm
40cm
2cm
MCP-PMT
Quartz + support jig
Focusing mirror
2cm
40cm
mirror(R=5m)
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ARICH for forward PID
• Proximity focussing RICH
• /K separation from 1.5 to
4 GeV/c
• Inside axial magnetic field
• Test at KEK Fuji beamline(2 GeV e-)
– Cherenkov ring observed
– 6 p.e./track
– 13.2 mrad resolution
Aerogel radiator
Position sensitive devicewith B=1.5Tesla
Cherenkov
photon
200mm
n~1.05
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JFY2009 JFY2010 JFY2011
Worst ScenarioWorst Scenario
Super Super
Best ScenarioBest Scenario
Best ScenarioBest ScenarioGovernment Government
Review Review
Council Council
Full BudgetFull Budget
Proposal Proposal ConstructionConstruction
Good Scenario Good Scenario
R&D BudgetR&D Budget
Proposal Proposal Super-KEKBSuper-KEKB
R&D R&D
Better Scenario Better Scenario
SupplementSupplement
Budget Budget
SupplementSupplement
Budget Budget
Feb-9, 2009
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Summary and conclusions
• We believe that we can build a Super Bfactory by upgrading the existing KEKBaccelerator and Belle detector
• We are now completing the R&D phase andaim at submitting the TDR soon
• There is great interest in our project in thecommunity, and new groups have joined ourefforts
• The SuperKEKB collaboration is emerging --we had our first collaboration meeting Dec.10-12, 2008 at KEK
• KEK DG has submitted a funding request toMEXT, and we are optimistic about theoutcome