KEKB Upgrade - HEPHY · KEKB Upgrade. 3 ~1 km in diameter Mt. Tsukuba KEKB Belle 8 GeV electrons on ... Aerogel Cherenkov cnt. n=1.015~1.030 Central Drift Chamber small cell +He/C2H5

The SuperKEKB ProjectChristoph Schwanda, Vienna

representing the Super KEKB collaboration

SuperB WorkshopLAL, Orsay,February 15-18, 2009

KEKB Upgrade

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)

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Luminosity history

Belle will have ~1/ab (~1 billion BB events)by the end of data taking in March 2010

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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)

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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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9

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Belle upgrade

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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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Beam background

The upgraded detector must be ableto handle (at least) 20x times more beamground

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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

Schedule

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A.Suzuki(KEK DG)Jan-4, 2008

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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

Backup

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Machine parameters of SuperKEKB

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Luminosity prospect

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