1

Weiguo Li

Institute of High Energy PhysicsSep. 16, 2002

Overview of BEPCII/BESIII PROJECT

BESIII International Review

Sep. 16-18, 2002, Beijing

2

Goals of the BESIII review• Examine the overall design of BESIII detector, if this design can accomplish the goals?

• Examine the technical feasibility of detector overall design, the designs of all the sub-systems

• Suggestions and opinions for important detector design choices, such as the magnet and the EMC

• Suggestions and comments for further detector design, R&D, detector manufacture, schedule and cost

3

Introduction

BEPCII Design

BESIII Design

BESIII Collaboration

Summary

4

Korea (4)

Korea University Seoul National University

Chonbuk National UniversityGyeongsang Nat. Univ.

Japan (5)

Nikow UniversityTokyo Institute of Technology

Miyazaki UniversityKEK

U. Tokyo

USA (4)

University of HawaiiUniversity of Texas at Dallas

Colorado State University Stanford Linear Accelerator Center

UK (1)Queen Mary University

China (18)IHEP of CAS

Univ. of Sci. and Tech. of ChinaShandong Univ., Zhejiang Univ.

Huazhong Normal Univ. Shanghai Jiaotong Univ.

Peking Univ., CCAST Wuhan Univ., Nankai Univ.

Henan Normal Univ.Hunan Univ., Liaoning Univ.

Tsinghua Univ., Sichuan Univ. Guangxi Univ., Guangxi Normal Univ.

Jiangsu Normal Univ.

Introduction

5

Data Collected with BESI and BESII Ecm (GeV)

Physics BES Data Other Lab.

3.10 J/ 7.8106 8.6106

3.69 (2S) 3.9106 1.8106

4.03 1.0105 LEP

4.03 DS, D 22.3 pb-1 CLEO

3.55 m scan m 5 pb-1

2-5 R scan R value,

QED, (g-2) 6+85 points 2, MarkI

Crystal Ball Pluto……

3.1 3.69 3.78

J/ (2S)

(3770)

5.8107

1.46107

~7 pb-1

BES Current StatusBES Current Status

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BESII Detector BESII Detector ((1995-1997 upgrade1995-1997 upgrade))

VC: xy = 100 m TOF: T = 180 ps counter: r= 3 cm MDC: xy = 250 m BSC: E/E= 22 % z = 5.5 cm dE/dx= 8.4 % = 7.9 mr B field: 0.4 T p/p=1.8(1+p2) z = 2.3 cm Dead time/event: 〈 10 ms

7

BESBES Main Physics Results

Precise Mass Measurement of lepton.

2-5 GeV R measurement.

Systematic study of (2s) decays.

Systematic study of J/ decays.

Obtain fDs from Ds pure leptonic decay.

Measure Br(DS ) in model independent way.

BES has 116 entries in PDG.

BES has 74 invited talk ， published 216 papers, 48 pape

rs in world-class journals.

8

Physics Window for BEPC Two major directions in world HEP:

– High Energy Frontier ： Search for Higgs particle and beyond STM

particles and phenomena.

– High precision frontier ： high statistics and high precision ， check

STM ， search for phenomena beyond STM.

Considering the new developments of world HEP, the main physics window

for BEPC is precise measurement of charm and charmonium physics, and s

earch for new phenomena.

Advantages: huge cross section at J/ and (2s) resonance

simple topology and low background at threshold

Important area to study QCD ， perturbative and non-perturbative QCD ，can search for new physics.

9

BEPC II Physic Goals

• Precise measurements of J/、 (2s) 、 (3770 ） Decays

• Precise measurement of CKM parameters

• Light quark hadron spectroscopy

• Excited baryon spectroscopy

• Other D and Ds physics: – precise measurement of D and Ds decays– measurement of fD, fDs – D0 –D0 mixing

• Check VDM, NRQCD, PQCD, study puzzle

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BEPC II Physics Goals （ 2 ）

• Mechanism of hadron production ， low energy QCD ：

precise R measurement• physics ： charged current ， m and m

• Search for new particles: 1P1 、 c ? 、 glueballs 、 quark-gluon hybrid 、 exotic states…

• Search for new phenomena: – rare decays;– lepton number violation; – CP violation in J/ and (2s) decays;

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BEPC Future Development: BEPCII

• Precise measurements need:

– High statistics → high luminosity machine

– Small systematic error→ high performance detector

• BEPC will run at J/ and (2s) ， with huge cross-sectio

n, also at (3770), 4.03 or 4.14 GeV for Ds

• Need to have major upgrade for machine and detector

(BEPCII / BESIII) ， to increase machine luminosity by

more than one order of magnitude with relatively small b

udget and in a relatively short time.

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Competition in tau-charm physics• CESR, USA runs at 10GeV for B physics, because it can hardl

y compete with two B factories ， on the other hand, there are

important and interesting physics at tau-charm energy region

as demonstrated at BEPC, plans to reduce the collision energy

by installing a series of SC wigglers, expected lum. （ 1.5 – 3)x

1032cm-2s-1 。• VEPP-4M, Novosibirsk, Russia, has a similar plan.

• BEPC/BES can not enjoy the advantage of unique e+e- collider

in this energy region any more ， strong competition.

• BEPC II single ring design can not ensure competitive edge in

the race.

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BEPC II Double ring Design• In the existing BEPC tunnel, add another ring, cross over at south a

nd north points, two equal rings for electrons and positrons. Advanced double-ring collision technology.

• 93 bunches ， total current > 0.9A in each ring. Collision spacing ： 8 ns.• In south, collision with large cross-angle （ ±11 mr ） .• Calculated luminosity ： 1033 cm-2 s-1 @ 3.78GeV.

• In north cross point, connecting SR beam between two outer rings, in south cross point, use dipole magnet to bend the beam back to out

er ring.• SR run ： 250mA @ 2.5 GeV.• Major detector upgrade ： BES III.

Luminosity of BEPCII is a factor of 3-7 of that of CESRc, more potential, and technically less challenge. Budget increased by 50 ％ .

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BEPC Upgrade: BEPC II BEPC Upgrade: BEPC II — — double ring double ring

e -

RFRF SR

e+

IP

15

BEPCIIBEPCII Design GoalsDesign Goals

Beam energy 1 – 2 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

Increase beam current ， reduce beam size

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Wood Model Space Study for Double Ring

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Luminosity Increase

)(

)()()1(1017.2)s(cm

*341-2-

cm

AIkGeVERL

y

bby

Micro-:y*=5cm 1.5 cm

Super-conducting magnetImpedance red. and SC RF cavity

z=5cm <1.5cm

D.R.: multi bunches h~400, kb=1 93

(LBEPCII/ LBEPC) D.R.=(5.5/1.5) 93 9.8/35=96

LBEPC=1.010 31 cm-2s-1 LBEPCII =110 33 cm-2s-1

Ib=9.8mA, y=0.04

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Means of lum. increase (E = 1.89 GeV)

parameter unit BEPC BEPCII

y* cm 5.0 ～ 1.5

Bunch number kb 1 93

y 0.04 0.04

Beam current Ib mA 35 9.8

factor for lum. increase

1 ～ 100

BEPCII cross-angle collision ： 2 x 11mr

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BEPCII BEPCII Main ParametersMain ParametersEnergy E(GeV) 1.89 Energy spread(10-4) σe 5.16

Circumference C(m) 237.53 Emittance εx/εy(nm) 144/2.2

Harmonic number h 396 Momentum compact αp 0.0235

RF frequency frf(MHz) 499.8 β*x /β*

y(m) 1/0.015

RF Voltage Vrf(MV) 1.5 Tunes νx/νy/νz 6.57/7.6/0.034

Energy loss/turn U0(keV) 121 Chromaticities ν’x/ν’

y -11.9/-25.4

Damping time τx/τy/τz(ms) 25/25/12.5 Natural bunch length σz0(cm) 1.3

Total current/beam I(A) 0.91 Crossing angle (mrad) ±11

SR Power P(kW) 110 Piwinski angle Φ(rad) 0.435

Bunch number Nb 93 Bunch spacing Sb(m) 2.4

Bunch current Ib(mA) 9.8 Beam-beam parameter x/ y 0.04/0.04

Particle number Nt 4.5×1012 Luminosity(1033cm-2s-1) L0 1.0

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BEPCII/BEPC/CESRc Comparison

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BEPCII BEPCII Key Technologies and ChallengesKey Technologies and Challenges

Linac Injection rate: 5 mA/min.

50 mA/min.

New positron source

Stability and reliability

Einj= 1.55-1.89 GeV

500MHz SC RF System

SC RF Technology

Power source and low level

Cryogenics…

Injection

Magnets

Power supplies

Vacuum system

SC Q magnet and IP

Beam instrumentation

Control system

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Linac UpgradeRequirements: Positron injection rate 5mA/min. 50 mA/min.; Energy 1.3 GeV 1.55 ~ 1.89 GeV;

Use 45MW Klystron,upgrade RF source, replace 8 aged acceleration tubes ；Bombarding energy for positron 150 MeV 240 MeV;

Electron gun beam intensity 5A10A ； Produce new positron source, improving efficiency ； Improve focus and orbit-correction system ； Repetition rate 12.5 Hz 50 Hz ； Pulse duration 2.5ns1ns ； Possibility of double pulse injection (fRF/fLinac=7/40);

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means and factors for increase injection rate

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SC RF System

Requirements ： Sufficient voltage Sufficient power reducing coupling instability stability, reliabilit

y

Measures: collaborate with SSRF, Cornell and KEK ， using existing technology.

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Super-conducting Cavity CESR-type Cavity (ACCEL) KEKB-type Cavity (Mitsubishi )

IHEP/KEK/SSRF collaborating group will optimize the cavity design, follow the manufacture process and technology, master the required techniques for operating and repairing the cavities.

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Interaction point and SC Q magnet field length (m)

四极线圈 Q 16.7 T/m 0.4

斜四极线圈 0.2 T/m 0.4

SR 偏转线圈 0.645 0.4

反抵螺线管 2.6 0.5

屏蔽螺线管 ~1.2 ~0.4

水平校正线圈 0.0528 0.4

垂直校正线圈 0.0528 0.4

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Beam Feedback System Challenge ： How to insure collision?

Beam-beam bending and scanning techniques ：Beam-beam bending ： accelerator physicsBending measurement ： beam instrumentationScan feedback ： automatic control

IP_Bump

Orbit data SteeringBeam-BeamDeflection

IP-BPM 二极校正铁IP Orbit Feedback

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BES III Expected Event RatesAt 1033,at J/ and 4.14 GeV, ~0.61033

Particle Energy Single Ring （ 1.2fb

-1 ）Double Ring (4

fb-1)

D0 7.0106 2.3107

D+ 5.0106 1.7107

Ds 4.14GeV 2.0106 4106

+- 3.57GeV3.67GeV

0.6106

2.91060.2107

0.96107

J/    3-4109 6-10109

   0.6109 2109

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BESIII Design Goals

• High event rate ： lum. :1033cm-2 s-1 and bunch spacing 8ns ， hardware trigger rate: 4000 Hz ， putting on mass medium: 3000 Hz.

• Improve detector resolutions , especially for photons

• Improve particle identification

• Enlarge detector solid angle acceptance

• Design interaction region to fit sc Q magnets

30Schematic of BESIII Schematic of BESIII DetectorDetector

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BESIII Main Sub-systems• CsI EM Calorimeter: E/E ~3.5%@1GeV (inc. dead material)

• MDC: small cell, Al field wire and He-based gas

P/P (1GeV) = 1.4 %@0.4T, 0.6 %@1T, dE/dx = 6-7 %

• Time of Flight: T: barrel 90 ps ； endcap 110 ps counter(RPC): readout strip width ： ~4 cm

• Luminosity Monitor(LM) L/ L = 3-5%• SC Solenoid ： 1 Tesla, I.R. 1.32 m, Length 3.8 m• New Trigger and Online system for multi-bunch and hi

gh lum. Operation, 4000Hz, 3000Hz to mass storage• New Electronics ： pipeline operation

• Offline computing: PC farm, mass storage

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Small cell, 46-47 layers

He based gas HeC3H8 ( 60:40)

Position resolution 130 m

Mom. Resolution

0.6% at 1 GeV at 1 Tesla

1.4% at 1 GeV at 0.4 Tesla

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cos=0. 93

S10

F1

40. 2

40

R871

R838

1750

R810R9

25R9

30R1

290

R130

0R1

320

R132

5R1

700

1740

2550

R31.

5R5

9

正公

差

负公

差

R400

R482

.5

1382

1330

1291

11

2800

正公差

负公差

正公差

801970

2050

( )配做

R102

0

R350

R242

5

R400

1721

1720

负公差

正公差

正公

差

负公

差

正公

差

负公

差

正公

差

负公

差

负公

差

正公

差

负公

差

正公

差

正公

差正公

差

1300负公差

( TOF)上层

2

2

1250负公差

( TOF)下层

BESIII mechanical structure

Dimensions need final

tuning

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Item

time measurement Charge measurementCount rateper channel

Information provided to trigger

Number of channel

σtINL Ran

ge

Cross-talk

Number

ofcha

nnels

σQ

INL

Dynamic

range

Cross-talk

Type Quant.

MDC 90000.5-1 ns

≤0.5%

0-400ns

 9000 5fc

≤2%

15 fc -1800fc

1%

30 k/s hit

TOF

+ CCT

 

352+104

≤25ps

0- 60ns

456 12bits(ENOB)

≤2%

20mv –4v

2-4 k/s hit 456

EMCBAR

         8064+1800

0.16 fc 200KeV

1 %

0.5fc -1500fc

0.3 %

1 k/s

SummationOf analog

 

EMC(End)

          1800

0.16fc 1 %

0.5fc -1500fc

0.3 %

1 k/s

SummationOf analog

 

Mu

Chan ~10000

     

Spec 

Considering multiple hit time measurement

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Sub-system BES III BESII

XY (m) = 130 250

MDC P/P (0/0) = 0.6 %(1 GeV) SC

1.4 %(1 GeV) Normal

1.7% √2 (1 GeV)

dE/dx (0/0) = 6-7 % 8.5%

EM Calorimeter E/√E(0/0) = 3.5 %(1 GeV)

z(cm) = 0.5cm/√E

20% (1 GeV) 3 cm /√E

Time of Flight T (ps) = 90 ps barrel 110 ps endcap

180 ps barrel

350 ps endcap

Counters 9- 10 layers 3 layers

Magnet 1.0 tesla Option 1 0.4 tesla Option 2

0.4 tesla

Comparisons between BESIII and BESII

36BESIII detector with existing magnet

Worse mom. Resolution,

Better low mom. efficiency

37

BESIII Expected Physics Results

Monte Carlo simulation show: because lum. Increase by two-orders of magnitude, a factor of 3 – 7 of that of CLEOc ， BES III can obtain many important results in tau-charm physics

Topics ：• Precise measure CKM parameters

• Precise R measurement

• Search for glueballs, determine spin and parity

• Search for 1P1

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Physics example 1 ： precise measure CKM matrix

• Measure pure-leptonic and semi-leptonic decay Br. Fracti

ons of charm mesons to determine Vcd and Vcs

• Measure hadronic decay Br. Fractions of charm mesons f

or determine Vcb

• Measure fD and fDs for determining Vtd and Vts

• Measure semi-leptonic shape of D and Ds for Vub

• CKM unitarity check

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Br. Fractions of D decays （ involving leptons ）

Decay

Mode

Input

Br(%)

Measured

Br(%)(80 pb –1)Relative Error (stat.)(5 fb –1)

3.4 0.6 %

0.4 1.5%

8.5 1.5%

0.03 evts

~340 evts

fD/fD ≈3%

e0 eKD

KD0

e0 eD

0D

0KD

e0eKD

D MeV220D f

13.036.3

17.059.3 04.042.0

05.041.0

8.08.8

0.17.7

44

40

Physics example 2 ： R measurement

Error Source BESII reach(%) BESIII goal(%)

Luminosity 2 - 3 1

Selection effi. 3 - 4 1 - 2

Trigger effi. 0.5 0.5

Radiation corr. 1 - 2 1

Model of hadron decay

2 - 3 1 – 2

Statistical 2.5 --

Total error 6 – 7 2 - 3

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Physics example 3 ： Search for 1P1

S) P 1

c

r = (1.2 – 3.3)×10-6

1P1: 450-1200 evts/year

ackground: S) c1, c2,,

42

Other expected physics reaches and background study by MC simulation will be covered by

Dr. Wang Yifang

Most of the main detector sub-systems will be covered by other speakers, I will say a few words about these sub-systems which are not presented separately today.

Interaction region

Mechanical preliminary design

Slow Control

43

Interaction RegionIt is very compact at IR, very close cooperation is needed in the designs of detector and machine components at IR

• Understand the space sharing, the support, vacuum tight

• Understand the backgrounds from machine and how to reduce them, good vacuum near detector is required

- Beam loss calculation (masks)

- Synchrotron radiation (masks)

- Heating effect (cooling if necessary)

• Understand the effects of the fringe field from SCQ to the detector

performances, the preliminary study shows that, field uniformity

should be better than 5% in most of the MDC volume

• Center of beam pipe will be a double-wall Be pipe

44

BESIII Mechanical design and Detector HallDetector on two rail pads to move in south-northIron Yoke Barrel~ 285 tons; endcap ~252 tons.

at both sides between barrel and endcap, there should be a slot of 1100x 80mm for each side of octagon on every terminal surface of the barrel of yoke, for cable space.

The thickness of layers of the barrel yokeare 30,30,30,40,40,80,80,80,150mm and gaps between layers are 40mm

The thickness of layers of the end yoke are 30,30,30,30,30,40,80,80,80 mm and gaps between layers are 40mm

45

Assembled Structure, test assembling at factory

46

Movable endcap yoke; reposition for field stability

endcap EMC supporting and moving design, removing and reconnecting cables should not change the gain.

47 Arrangements of electronic crates, moving with detector

48Arrangements for cooling water, gas, cables

1. Temperature measurement: > 1000

EMC CsI , 600 ; MDC 16; , 150; electronics crates, 300; cable rack, 100; environment, 100;

2. Humidity measurement: ~250

CsI, 200 ; MDC, 8; electronics, 20; environment, 30;

3. Low HV of VME crates: 500.

4. MDC gas ： 8.

5. Voltage of power supply: several.

6. Other measurements? Magnetic field; parameters in SC magnet and cryogenics; HV parameters for detectors; radiation dose; He leakage; flammable gas;others.

Slow control system Required measurements from detector and electronics

ONE WIRE BUS can be used to read these signals out

Probe/master, doing R&D

64 bit W. A. O （ unique code worldwide), 12 bit DATE

Temperature probe: DS18B20, 22 RMB/probe

humidity probe: LTM8802, ~150 RMB/probe

1. Humidity range: 1~99% ， typical precision: 3%.

2. Temperature range: -30 ~60℃ ℃， accuracy 0.5 ℃

D . C voltage probe: DS2438/ LTM8805, several dozens of RMB/probe

analog voltage:0 ～ 10V （ resolution ： 0.01V ）

Light-decoupling between PC and master to reduce noise

pickup, LTM － 4850/2 dual-port RS － 485 card

51

BESIII Key Technology and Challenge• Control background (with machine people), take good quality data

at high luminosity. Small ring is more problematic with background

and radiation dose!

• Design and operate SC magnet

• Stable operation of MDC(>30000 wires), obtaining better resolution

• Obtain best possible EMC energy resolution, by quality

control in detector construction and good calibration systems

• Obtain best possible TOF resolution, all factors controlled

• Build a trigger and DAQ system, with required data transfer rate

and good performance (specifications, reliability)

52

Some preliminary design issues, such as TOF readout electronics, EMC support structure etc are not finalized

The tasks for offline systems are defined, people are assigned, the important issue is that the overall structure of offline system should be decided ASAP, so people can start to work on the software

Determination of some of main design options

• Magnet? super-conducting/existing normal; performances and cost

• Particle ID? (TOF/ Ĉerenkov based)

Cost and schedule concern

• Cost for EMC, SC magnet and electronics is most crucial;

• MDC, EMC and SC magnet (including iron structure) on critical path;

53

BESIII will be competitive in producing good physics results after its completion; can help to master advanced technology related to detector design and construction, fast electronics, DAQ and data analyses, help to catch up with world level or close the gap.

But, construction of BESIII and obtaining world class results, are big challenge to Chinese HEP experimentalists, need to master new techniques, such as super-conducting, low-Z small cell MDC; high precision EM calorimeter; pipeline fast electronics, fast data acquisition, huge data storage and processing; Need international collaboration （ Japan, US, Korea) 。

54

• Conceptual design started in 1999.

• Feasibility study started in the summer of 2000 ， completed in Aug.

of 2001.

• Preliminary design started in the summer of 2001 ：– Machine finished physics design, requirements for sub-systems ar

e determined;

– Sub-system designs are progressing well

– Detector design is progressing well, prototype and detailed mechan

ical design

– Expected to finish preliminary design in 2002

• Upgrade of Linac started.

• R&D for key technologies started ： SC cavity, Q magnet

Project Status

55

Feasibility Study/Design Review•    BEPC II feasibility international review ( 01. 4. 2 – 6, Beijing)

26 experts reviewed the feasibility of machine and detector

•    BEPC II machine feasibility review ( 01. 7. 29 - 30 Beijing)

21 domestic experts reviewed machine feasibility and preliminary d

esign.

• BESIII International Workshop (01.10.13 – 15 Beijing)

• International technical review of machine preliminary

design at SLAC, May, 2002

• BESIII preliminary design review, in Sep. of 2002

56

Project Schedule and Budget• Done Feasibility Study Report submitted. End of Sep. of 2002 Preliminary Technical Design Report June 2003 R&D and prototype May 2004 BEPC run• July 2002 June 2006 Construction• May 2004 Nov. 2004 BESII dismounting and Linac upgrade • Nov. 2004 Jan. 2005 Linac commissioning• Jan. 2005 Apr. 2005 SR run• Apr. 2005 Jan. 2006 Storage ring assembling• Jan. 2006 June 2006 Commissioning of storage ring• June 2006 Sep. 2006 BESIII detector moved to beam-line• Sep. 2006 Commissioning machine and detector

Very tight schedule

57

BESIII Schedule

 2001.1~2002.6 Preliminary design

2001.7~2003.6 R&D of critical parts

2002.7~2005.9 Construction of detector components

2003.1~2004.6 Construction of return yoke

2002.3~2004.12 Design of super-conducting magnet

2004.7~2004.11 BESII disassembling

2004.12~2005.3 BESIII iron yoke assembling (with magnet)

2005.4 Commissioning of cryogenics

2005.5~2005.8 Magnet field measurement （ with SCQ ） 2005.9~2006.1 Assembling of other detector components

2006.2~2006.6 Commissioning of BESIII detector

2006.7~2006.8 BESIII moved to beam-line

2006.9~2006.12 Commissioning of BEPCII+BESIIISome sub-systems maybe problematic to meet the schedule

58

BEPCII Team and Administration

• BEPC II project leaders and headquarter are established;

• 4 Major systems, Linac; Ring; Detector; Technical support( cryogenics).

• Most of responsible persons for sub-systems are appointed.

• Some procedures are established, quality control; budget control; technical review; etc.

59

BEPCII BEPCII Budget (10K RMB)Budget (10K RMB)

Item Budget Percentage

1. Linac 4400 6.87%

2. Ring 22900 35.78%

3. Detector 21000 32.81%

4. Infrastructure 5780 9.03%

5. Assembling 2500 3.91%

6. Building 320 0.50%

7. Others 3300 5.16%

8. Overhead 600 0.94%

9. Contingency 3200 5.00%

Total 64000 100.00%

60

BESIII Budget (10K RMB)

Item Price Quantity Subtotal Total

1 Beampipe(masks) 115

2 MDC 1947

2-1 End plates 1000

2-2 Material and wiring 695

2-3 HV cards and cables 102

2-4 Clean room 40

2-5 Cosmic test 65

2-6 Others 45

3 EMC 8990

3-1 CsI crystals ~10000 7200

3-2 Si photo-Diodes ~10000 600

3-3 Crystal meas. device 160

3-4 Monitoring 180

3-5 Supporting 650

3-6 Assembling 60

3-7 Others 140

61

4 TOF 1075

4-1 Scintillator 360 168

4-2 PMT R5924 500 750

4-3 New HV system 84

4-4 PMT Base 25

4-5 Mechanical 18

4-6 Prototype R&D 30

5 counters 330

5-1 RPC 280

5-2 Lab and R&D 50

6 SC Magnet 3570

62

7 Electronics 3495

7-1 MDC 9000T+

Q 1500

7-2 TOF 448 130

7-3 EMC 10000 1600

7-4 Muon 10000 265 8 Trigger and DAQ 1178 9 Gas and enviro.

Monitoring 300

Grand total 21000

63

BEPCII Domestic Collaboration

Participation from other Institutes and Universities from

China, in charge of one sub-system or collaboration with

IHEP• Shanghai Synchrotron Light Source

– 500 MHz RF system

• Shanghai Institute of Ceramics ： CsI crystals

• Beijing University ： RF system, detector

• Qinghua University ： Accelerator technique, detector

• University of Science and Technology of China ： Detect

or, readout electronics

64

BESIII Domestic Collaboration

Design, MC simulation

Sub-detectors R&D and construction

Electronics R&D and manufacture

Online/Offline software

Software package

Reconstructions

Calibration

Physics study

In charge of some sub-system or send people to IHEP

65

BEPCII International Collaboration International collaboration played an important roll in BE

PC/BES project ， Expect to play major roll in the design

and construction of BEPCII / BESIII ：– BNL of US: SC Q magnet;– SLAC of US: Key machine technology, design reviews;– KEK of Japan: SC cavity and SC solenoid… – Improve technical excellency and research capability Advice and help in design and construction in various systems; Technical review and follow-up in detector design, construction and commissioning.

66

BEPCII / BESIII can attract international participation, especially in detector and physics; Share cost ， improve detector performances

Institute of High Energy Physics, BeijingTsinghua University, Beijing Beijing University, Beijing

Sichuan University, Chengdu University of Science and Technology of China, Hefei

University of Hawaii, Honolulu Shandong University, Jinan Nanjing University, Nanjing

Shanghai Institute of Ceramics, Shanghai National Central University, Taipei

University of Tokyo, Tokyo University of Washington, Seattle

Huazhong Normal University, Wuhan

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More Institutes from US and Japan may join,Korea has interest in participating

Should form BESIII international collaboration according to international standard:Institutional board; Executive board; Spokesperson; etc.

International review/Documentation/

video conferencing

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Summary BEPC/BES meet opportunity and challenge in the field of tau-cha

rm physics.

BEPCII double-ring design luminosity 1033 cm-2s-1at 1.89 GeV ，with major upgrade of BES ， can insure an important roll in world HEP, especially in tau-charm physics.

BEPCII/BESIII is technically feasible, should be started as soon as possible.

BESIII has a baseline design, optimization is needed

Strength domestic collaboration ， stimulate developments of relevant technologies in China.

International collaboration in BEPCII/BESIII construction.

BESIII Collaboration should follow international standard.

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Hope this review meeting can help BESIII to improve its design

Thanks

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Sub-system BES III CLEOc

XY (m) = 130 110-130

MDC P/P (0/0) = 0.6 %(1 GeV) SC

1.4 %(1 GeV) normal

0.5 %(1 GeV)

dE/dx (0/0) = 6-7 % 6%

EMC E/√E(0/0) = 3.5 %(1 GeV)

z(cm) = 0.5cm/√E

2.3 %(1 GeV)0.5 cm /√E

TOF T (ps) = 90 ps Barrel 110 ps endcap

RICH

counter 9- 10 layers 3layers

magnet 1.0 tesla option 1 0.4 tesla option 2

1.0 tesla

Comparison Between BESIII and CLEOc

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Infrastructure BEPCII needs some building construction: halls for Cryogenic system and additional magnet power supplier; improving shielding of some buildings, etc. Major systems:

– New cryogenic system: capacity of 1kW/4.5K– BEPCII power consumption to be doubled

• 110kV transformer: 6300kVA 12500kVA• New electric crates and apparatus

– Increase capacity of air-conditioning– Improve water circulation system– Improve pure water system

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More room is needed for electronics, two more steps

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High Energy Physics 1 ） BEPC future development BEPC II:

- BEPC / BES major upgrade, increase luminosity by more than one order of magnitude;

- Main physics goal: J/ , ′and D/DS physics;

2 ） Strength non-accelerator experiments: Cosmic ray,

astro-physics experiments, neutrino experiment…;

3 ） International Collaboration

Chinese Academy of Sciences ：The strategy for Chinese HEP and Advanced Accelerator technology

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Science-education Leading Group of State Council, the 7th meeting (2000.7.27), discussed the report by CAS about HEP Conclusions ：（ 1 ） Approval in principle of 《 Report about the future development of Chinese HEP and advanced accelerator technology 》 by CAS. Meanwhile, CAS should consult further with experts in China and abroad ， strength and attract more international collaboration. （ 2 ） In view of the success of BEPC, approval of major upgrade of BEPC, with a budget of 400 M RMB.With relatively small invest, continue to obtain high-level achievements. (At that time, it was meant single-ring)

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BEPCII Superconducting CavitySuperconducting Cavity

北对撞点

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BEPCII Vacuum system At designed current dynamic vacuum （ curve 810-9 ， IP 510-10 )

reduce impedance, avoid instability.

Measures IP use big pump, Smooth vacuum chamber, avoid gap and cavity;

Absorb SR photons;

Positron ring vacuum chamber tim coated, reduced second emission.

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磁场强度 有效长度(m)

四极线圈 16.7 T/m 0.4

斜四极线圈 0.2 T/m 0.4

SR 偏转线圈 0.645 0.4

反抵螺线管 2.6 0.5

屏蔽螺线管 ~1.2 ~0.4

水平校正线圈 0.0528 0.4

垂直校正线圈 0.0528 0.4

IP and SCQ MagnetIP and SCQ Magnet