Status of BESIII Representing BES collaborationWeiguo LiIHEP, CASliwg@ihep.ac.cnICHEP04Beijing, Aug. 18, 2004

BEPCII/BESIII ProjectBESIII Design and Current StatusSchedule and CollaborationSummary

BEPCII/BESIII Project Covered by Zhang Chuang in this sessionTwo rings

BEPCII Design Goals

Beam energy

1 2.1 GeV

Optimal energy

1.89 GeV

Luminosity

1 x 10 33 cm-2s-1 @ 1.89 GeV

Linac requirements

Full energy injection: 1.55 1.89 GeV

Positron injection rate > 50 mA/min

Dedicated SR

250 mA @ 2.5 GeV

Expected Number of Events in One Years Running

Physics Channel C. M. Energy (GeV) Peak Lumi. (1033cm-2s-1) Cross Section(nb) Events per Year J/3.0970.6~3400101093.6701.0~2.4121063.6861.0~6403.0109D3.7701.0~525106Ds4.0300.6~0.321.0106Ds4.1400.6~0.672.0106

BESIII Detector

BESIII Main Parameters

systemBES III XY = 130 mMDCP/P = 0.5 %(1 GeV) dE/dx = 6-7 %EMCE/E = 2.5 %(1 GeV) z,= 5-6mm (1 GeV)TOFT = 90-100 ps Barrel 110 ps endcap counter9- 8 layersMagnet 1.0 tesla

Main drift chamberInner diameter: 63mm; Outer diameter: 810mm; length: 2400 mm;43 sense wire layers.Inner cylinder: 1.2 mm Carbon fiber, outer cylinder: 11 mm CF with 8 windowsOuter endplate: 18 mm; stepped section 25mm; Al 7075 6796 Signal wires : 25 mm gold-plated tungsten 21884 Field wires: 110 mm gold-plated Aluminum Small cell: inner---6*6 mm2, outer--- 8.1*8.1 mm2,Gas: He + C3H8 (60/40)Wire resolution < 130mMomentum resolution@1GeV:

dE/dX resolution: 6-7%.

Blue/red Stereo wiresBlack:Axial: 12+7 wiresStructure and layer arrangement

Cell structureDrift velocity vs field

3

2.332.322.442.34

0.9240.9242.682.59

2.792.842.92.83

1.2071.2072.982.89

2.9433.082.99

1.4191.4193.163.07

3.093.163.223.13

1.7371.7373.373.31

3.381.9553.473.4

2.232.233.583.52

3.532.4063.633.57

2.732.733.73.65

3.683.0083.743.7

3.363.363.773.75

3.793.5343.5343.76

4.5C

28.5C

28.5C

4.5C

4.5C

28.5C

E/P(V/cmTorr)

(cm/s)

Sheet1

0.7522.332.342.322.44

0.9242.592.68

1.1282.792.832.842.9

1.2072.892.98

1.3162.942.9933.08

1.4193.073.16

1.5043.093.133.163.22

1.7373.313.37

1.9553.383.43.47

2.233.523.58

2.4063.533.573.63

2.733.653.7

3.0083.683.73.74

3.363.753.77

3.5343.793.76

Sheet1

4.5C

28.5C

28.5C

4.5C

4.5C

28.5C

E/P(V/cmTorr)

(cm/s)

Sheet2

Sheet3

Resolution vs Drift Distancecosmic ray16.4mm cell 14.0mm cell Primary ionization fluctuationsDistortion of fieldWire resolution of 130 m is achievable; beam test done at KEK, data is being analyzed;Outer and inner cylinders are ready; Endplates are in fabrication; feed through prototypes are fine;wiring machine will be ready soon;prototype of readout electronics.Wiring will start at the end of 2004

Time of Flight CountersBarrel2*88 scintillator bars, BC408, 2.32 m long, 5cm thickEndcap48+48 scintillator barsresolution100-110 ps/layerPMT: Hamamatzu R5942Endcap sideviewBarrel mechanical

K/ separation: 0.8GeV.Factors contribute to the time resolution

Time of Flight systemBeam test finished, intrinsic timing resolution of BC408 reached ~90ps for barrel and ~95ps for endcap, comparing with Eijen 200 scintillatorsPMT tested in 1T magnetic field Electronics using HPTDC tested, resolution ~ 18 ps Currently under study:reflecting materials for scintillator barsTesting facility for mass productionPID with Aerogel Cerenkov countersStart to order PMT and scintillator in 2005

Beam TestIntrinsic resolution of BC408 and EJ200 BarrelEndcap

CsI(Tl) EMC6240 crystals, (5.2x 5.2 6.4 x 6.4) x 28cm3 PD readout, noise

no partition wall Mechanical support structure

Crystal productions have some delay, the quality is fine, no big problems expected;The devices for measuring crystal properties and PD are designed and are functioningThe EMC monitoring system is designedElectronics are on schedule,

Light output > 33% of reference crystal~5000 e/MeVUniformity < 7%Radiation hardness Light output > 80% after 1kradCrystal size: Lateral, +0 -200mCrystal quality control

BESIII Super-conducting magnetCoil: Single layer solenoid ,steady fieldCooling mode: In-direct cooling by two phase flow liquid helium Cable: Pure Al stabilized NbTi/CuFabrication technology:Inner windingCold mass support: GFRP tension rodThermal shield: Liquid Nitrogen plus multi-layer thermal insulationFlux return: Barrel/End yoke, pole tip

Cryostat Inner radius1.375m Outer radius1.7m Length3.91mCoil Mean radius1.485m Length3.52mCable dimension3.7mm*20mmElectrical parameters Central field1.0T Nominal current3250A Inductance2.1HStored energy9.5MJCold mass3.6tonTotal Weight14.6tonRadiation thickness2X0

BESIII Super-conducting magnetSC cableHitachi cable Ltd., deliveredSC magnetCollaboration with WANG NMR INC., US. Current status Engineer design completedWinding machine readySupporting cylinder will be ready end of Aug. Engineer design of cryogenics is nearly doneStart winding the magnet this Sep. Magnet cooled down summer of 2005, then field mapping

m system : RPC9 and 8 layers, 2000 m2Bakelite, no linseed oil 4cm strips, 10000 channelsProduction started (endcap)Noise less than 0.04 Hz/cm2

Covered by ZHANG Jiawen in this session

Expected PerformancesSolid angle: 0.89Barrel: 0.62- 0.77Position resolution: 1.2 cm Minimum momentum0.4GeVEfficiency: > 95%Punch-through:

RPC prototypes

R&D: under neutron radiationAfter some time for recovery, all properties back to the level almost the same as before radiation.

Trigger system Event rate: Good event rate: ~ 2000 HzBhabha event rate: ~800HzCosmic-ray rate: 10:1Beam background rate: 10000:1Total event rate 4000 HzPipeline: BEPCII in multi-bunch mode ( 93 )bunch spacing: 8ns trigger latency: 6.4 sevents stored in pipeline buffer No dead time due to triggerLargely use optical fibers, FPGA,

Trigger systemconfigurationGlobal Trigger Logic6.4 sTOFMDCEMCMUDISCDISCMu trackDISCTrigSumTrack FinderEtotal EnergyHit/Seg CountTrack Seg. FinderDAQRFTTCTC SumL1PCLOCKTrack MatchEnergy BalanceCluster Counting

Trigger simulation: MDC triggerTrigger SystemDesign done,Trigger efficiency and background rejection meet the requirementsTrigger boards being Designed.

DAQ Systemdata transfer requirementsL1 trigger rate: 4 KHz Event Size: 12 KBytesBandwidth required after L1: 48 MByte/secBandwidth required on tape: 36 MByte/sec> 1000 current BESII system

DAQ Systemconfiguration

File Server

Online Farm PCs

1 Gbps Switch

Run Control

Histogram Display

Event Display

Fast EthernetSwitch

FarmSupervisor

...

MDC

Fast Ethernet

VME Crates (16)

Readout PCs (4)

TOF

Fast Ethernet

VME Crates (2)

Readout PC (1)

EMC

Fast Ethernet

VME Crates (16)

Readout PCs (4)

MUC

Fast Ethernet

VME Crates (4)

Readout PC (1)

TRG

Fast Ethernet

VME Crates (10)

Readout PCs (2)

Some tests of power pc

Chart1

0.24533333310.13199999950.24466666650.0839999982

0.14266666660.13233333280.12633333310.0756666668

0.13799999970.13233333320.10383333280.0716666666

0.13633333330.13233333320.08833333320.0681666665

0.13654166660.13233333320.08320833330.0678749999

Ttotal(opt=1)

Ttotal(opt=0)

Tcpu(opt=1)

Tcpu(opt=0)

Event Num

Time(s)

Sheet1

NevtOnet(opt=1)Onet(opt=0)Ttotal(opt=1)Ttotal(opt=0)Tcpu(opt=1)Tcpu(opt=0)Oidl(opt=1)Oidl(opt=0)

16.1333333283.2999999880.24533333310.13199999950.24466666650.08399999820.0166666661.200000032

27.1333333286.6166666420.14266666660.13233333280.12633333310.07566666680.8166666742.8333333

413.79999996813.2333333240.13799999970.13233333320.10383333280.07166666663.416666696.066666664

827.26666665626.4666666480.13633333330.13233333320.08833333320.06816666659.60000001612.83333334

1654.61666664252.9333332960.13654166660.13233333320.08320833330.067874999921.3333333225.783333342

Chart2

0.0360.1520.056

0.0340.1480.054

0.0340.1470.054

0.0340.14750.0545

0.033750.148750.05425

Tcpu(notbl)

Tcpu(tbl)

Tcpu(GEO)

Event Num

Time(s)

Tpack

Sheet2

NevtOcpu(notbl)usOcpu(GEO)usOcpu(tbl)usTcpu(notbl)sTcpu(GEO)sTcpu(tbl)s

1914380.0360.0560.152

21727740.0340.0540.148

434541470.0340.0540.147

8681092950.0340.05450.1475

161352175950.033750.054250.14875

Chart3

0.1760.2920.0360.1520.0840.056

0.137670.251670.0340.1480.075670.028

0.119670.232670.0340.1470.071670.014

0.109170.222670.0340.14750.068170.007

0.105130.220130.033750.148750.067880.0035

Total (no Calibration)

Total (Calibration)

EB (no Calibration)

EB (Calibration)

Network Transfer

DMA Transfer

Number of Events / Interrupt

Time (s)

The CPU Usage

Sheet3

NevtTnet(opt=0)Tpack(notbl)TdmaTpack(tbl)T(opt=0,notbl)T(opt=0,tbl)

10.0840.0360.0560.1520.1760.292

20.075670.0340.0280.1480.137670.25167

40.071670.0340.0140.1470.119670.23267

80.068170.0340.0070.14750.109170.22267

160.067880.033750.00350.148750.105130.22013

Beam pipe and shieldingBe beam pipe: 30 cm long, 63mm in diameter, 2 layers10-20 m Gold plating to reduce SR backgroundsHOM power: 200W, SR: < 24 WLiquid cooling channel between walls20 mm Tungsten shielding

Beam background: a serious issue1.89 GeV @ 1 AmpAll Cu surfaces

Total Beam-related BackgroundsBackgrounds are simulated from - Synchrotron Radiation; - Beam-gas; - Touschek effect; - Injection.With some masks and shielding near detectorSingle rate Max: at MDC 40 K; TOF: 10KDose/year at endcap EMC Max:~210rad/year, Ave:~ 50rad/year.Should be carefully monitored

BESIII Offline Software System (BOSS) A Team has been set up, most of the tasks are assignedCompleted:Three versions of software FrameworkCurrently based on GaudiA GEANT4 based MC with all sub-detectorsPreliminary reconstruction codes with most sub-detectorsThree releases planned before end of 2006Need more people to work on the reconstruction and prepare for the calibration

4 - tracks in BESIIIp=0.5 -1.5GeV|cos|

BESIII mechanics and return yoke

Engineer design completedContract for mechanics and return yoke awarded Pre-assembly this Nov.Start assembly next Feb.Preparation for installation started

BESIII StatusDesign has been finishedMost of the R&D work successfulDetailed Budget and CPM available Most of the budget have been contractedMass production has been started:CsI CrystalsRPC muon chambersSupport structure and YokeSuperconducting magnetDrift chamber structure

BESIII Schedule11/2004: supporting structure/yoke installation2-3/2005: endcap muon chamber installation5/2005: magnet installation10/2005: magnetic field mapping2/2006: EMC installation3/2006: MDC/TOF installation7/2006: BESIII debug and commissioning, Cosmic ray10/2006: BESIII detector in beam-line11/2006: commissioning detector/machine

A few items are on critical path for BESIII Mechanical support and Yoke Mechanical support of Barrel EMC; Crystal production Super-conducting Magnet Offline softwareTechnical Challenge Background issues PID, MDC, EMC performance; DAQ system

BESIII Collaboration There are about 18 Chinese institutes in BES collaboration, about 10 are actively involved in BESIII project, Physicists from US and Japan are participating in BESIII project, More foreign participants are welcome.Contact persons:liwg@ihep.ac.cn or yfwang@ihep.ac.cn

Summary BESIII project is in good shape right now, We have to work hard to meet the challenges and difficulties ahead of us. I believe we should be able to complete BESIII project on time and with good quality, and start to take data in 2007.

Thanks

BEPCII MilestonesMay. 04 Oct. 04. : Linac upgrade BESII detector removed Nov. 04 March 05: SR running April 05 Jan. 06: Long shutdown Remove existing ring Install two ringsCryogenics system ready for SC devices, field mappingFeb.- Sep. 06: Tuning of machine + SR running Oct. 06 : BESIII detector moved into beam lineNov. 06 Feb. 07 : Machine-detector tuning. Physics run by March 2007

Crystal size:front5.2cm x 5.2cm rear 6.4cm x 6.4cm length28cmCrystal production

QuantitySaint-Gobain3000SIC1920Hamamatzu1320

EMC support module ( 1/60 )

BESIII Main Detector ComponentsSmall cell, He gas based drift chamberTime of Flight CountersCsI(Tl) crystal calorimeterRPC muon chamber system Super-conducting magnet of 1T