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The progress of BESIII

The progress of BESIII. Guilin, Oct. 31, 2006 Yuekun Heng ( hengyk@mail.ihep.ac.cn ) Institute of High Energy Physics, CAS, China. Outline. BEPCII status Progress of BESIII Physics potential and detector targets Drift Chamber Time of Flight EM Calorimeter Muon detecor

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The progress of BESIII

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  1. The progress of BESIII Guilin, Oct. 31, 2006 Yuekun Heng (hengyk@mail.ihep.ac.cn) Institute of High Energy Physics, CAS, China

  2. Outline • BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detecor • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  3. Preface • Direction of Experiment of accelerator HEP • Big quantity -> collider • High Precision -> detector • BEPC/BES made many achievements in 15 years • Big competition from CESR: 10 times of Lum and better detector • Government approved BEPCII/BESIII project in the end of 2003

  4. BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detector • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  5. BEPCII:a high luminosity double–ring collider SC RF Two rings tunnel Government approved, and stared construction from end of 2003

  6. BEPCII Design goal Dual purpose machine It is possible to increase the c.m. energy to 4.6 GeV

  7. Design Goals and Main Parameters

  8. 37 10 -2 -1 L (cm sec ) 36 10 KEK B and PEP II 35 10 GLC 34 10 KEK B PEP II DAFNE2 BEPCII 33 CESR 10 CESRc LEP DAFNE 32 10 TRISTAN VEPP2000 PETRA DORIS 31 10 VEPP4M BEPC SPEAR VEPP2M 30 10 ADONE E (GeV) 29 10 cm 1 10 100 1000 e+-e- Colliders: Past, Present and Future L (cm-2 s-1) SUPER FACTORIES FACTORIES COLLIDERS E (GeV)

  9. Linac Status • Installation complete • new electron gun; • new position source; • new rf power (klystrons and modulators • Most design specifications reached at 1st test run.

  10. BEPCII Linac achieved Performances note：1）Two rf power stations were not in operation at the time. 2）The values for 1.89 GeV is extrapolated from those of 1.30 GeV，should be measured when the energy is at 1.89 GeV.

  11. Status of Storage ring • most of the systems have been completed • Major magnets • super-conducting RF cavities and • super-conducting quadrupole magnets, • beam pipes; kicker; beam instruments; • control system; • vacuum system as well as the cryogenics; • magnet sets installedLast month,

  12. Magnet System Bending magnets Quadrupole magnets Sextupole magnets Dipole correctors

  13. Storage ring magnets installed in Sep. 2006

  14. BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detecor • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  15. Charm Productions at BEPCII Average Lum: L = 0.5×Peak Lum.; One year data taking time: T = 107s Nevent/year = exp L T

  16. Charmonia production at BESIII • J/ • (2S) • (3770) • (4040) • (4160) Ecm of BEPCII 2.0 GeV -4.2 GeV charmonium + states from their decays

  17. Some topics Details pls refers to <<BESIII physics book>> • Charm physics at threshold • Absolute Branching Ratio • Leptonic Decay and Decay Constant • Semileptonic Decay and CKM Matrix • Physics Beyond Standard Model • D0D0 Mixing • CP violation • Rare Charm Decay • Summary • Search for hc(1P1) state • Hadronic decay dynamics and “” puzzle • The continuum amplitude and the data taking strategy • J/ψ study via ψ(2S) sample • e+e-charmonium+X for a study of charmonium production mechanism

  18. BESIII Detector • Two rings, 93 bunches: • Luminosity • 1033 cm-2 s-1@1.89GeV • 6 1032 cm-2 s-1@1.55GeV • 6 1032 cm-2 s-1@ 2.1GeV Magnet: 1 T Super conducting MDC: small cell & He gas xy=130 m p/p = 0.5% @1GeV dE/dx=6% TOF: T = 100 ps Barrel 110 ps Endcap Muon ID: 9 layer RPC Data Acquisition: Event rate = 3 kHz Thruput ~ 50 MB/s EMCAL: CsI crystal E/E = 2.5% @1 GeV z = 0.6 cm/E Trigger: Tracks & Showers Pipelined; Latency = 6.4 ms The detector is hermetic for neutral and charged particle with excellent resolution , PID adequate, and large coverage.

  19. BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detecor • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  20. Drift Chamber The BESIII main drift chamber (MDC) is one of the most important sub-detectors. Its main functions are: 1)Precise momentum measurement, to achieve this, particular cares should be taken to minimize the effects of multiple Coulomb scattering in the design; 2)Adequate dE/dx resolution for particle identification; 3)Good reconstruction efficiency for short tracks from interaction point; 4)Realization of charged particle trigger at level one; 5) Maximum possible solid angle coverage( ～90%4 π Sr.) for charged track measurement. Expected performance

  21. DC Parameters R inner: 63mm ; R outer: 810mm Length (out.): 2582 mm Inner cylinder: 1.2 mm Carbon fiber Outer cylinder: 11.5 mm CF with 8 windows Sense wire : 25 micron gold-plated tungsten (plus 3%Rhenium ) --- 6796 Layers (Sense wire ): 43 Vertex Chamber is saved. Gas: He + C3H8 (60/40) Cell: inner chamber --- 6 mm outer chamber --- 8.1 mm

  22. Inner Chamber • Consists of one inner cylinder, two end-plates and connection rings . • Inner cylinder is made of Carbon fiber, thickness is 1.2mm, to deduce the material • Supports 8 anode layers (all stereo layers ) • Assembled into the outer chamber after wiring

  23. Endplate (stepped section ) • Constructed of 6 precision drilled plates • Connection with 3 mm thick stainless steel bands • Each of 6 plates contains 2 anode layers • Layer spacing is uninterrupted between plates

  24. Endplate (ourter section) • The end-plates outer section : diameter 1.6m, 21152 holes (Φ3.2+0.025 ), the position precision : Φ 0.050。 • The drilling of the outer section (conical endplates) was completed in April last year ( about 6 months lost). • The drilling machine is a programmable machining center . The hole’s diameter and the position can be measured at the precision of 0.01mm with a three coordinates measuring instrument.

  25. Outer cylinder • The outer cylinder is consisted of two Al rings supporting the endplates and a carbon fiber cylinder shadowing the barrel of the calorimeter , 8 windows , thickness of 11.5 mm. The outer cylinder (left) axial motion is less then 0.06 mm at 5,000Kg pressure. • The inner cylinder is is consisted of two Al rings connected to the endplates of the inner chamber and a carbon fiber cylinder, thickness of 1.2mm. The inner cylinder (down right) axial motion is less then 0.06mm at 500Kg .

  26. Feedthrough • Three parts: the outer part is an insulating bush for high voltage insulation; the middle part is a copper tube for locating an inner tube and a high voltage connector ; the inner part is a small tube for wire fixing. The small tube is made of copper for sense wires, and aluminum for field wires. The crimping method is used. • Vectra A130, a kind of liquid crystal copolyester with 30% glass fiber. • Two kind of length—25mm &18mm for different thickness of the end-plates. • Outside diameter: 3.2mm—0.025mm, • Concentricity of the position hole: 0.025mm.

  27. Wire Stringing(outer chamber) • Positioning the holes (up and down ) in vertical ; wire with a small weight is through in the hole in the upper endplate and through out from the hole of the lower endplate; the wire is crimped in the feedthrough located in the hole of upper endplate; the wire is through a feedthrough located in the hole of lower endplate; tensioning ,crimping and cutting by the worker. • Stepped section wire stringing : a worker have to stand in a support inside the chamber to work for the wiring on the upper endplate .

  28. Beam test in KEK • A prototype of the BESIII drift chamber was tested with He/C3H8 (60/40) gas mixture in a 1T magnetic field at the π-2beam line of KEK 12GeV PS last year. The spatial resolution is better then 130 µ m, the cell efficiency over 98%, the dE/dX resolution better 5% and 3σ π/k separation exceeding 700MeV/c.

  29. MDC electronics • Completed a 160ch. Prototype Beam tests with a full length MDC prototype Beam test with our sub-detectors • Completed a 512ch. Prototype Full tests with real setup, all spec. are fulfilled. • Mass production started • By the end of the year, all electronics board should be tested and installed

  30. BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detecor • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  31. TOF Targets • Time resolution 1-layer (intrinsic): <90 ps, improve ~2 times comparing BESII • Non-TOF effects:~60ps • Time resolution of two layers is 100ps to 110ps for kaon and pions. • K/ separation: 2  separation up to 0.9 GeV/c. Already plan on upgrade Capability of K/ separation

  32. CsI Calorimeter Barrel TOF Drift Chamber Endcap TOF Structure of barrel TOF • Banded to MDC outer barrel of Carbon-fiber • R-direction space: 81cm-92.5cm • Scintillator Length: 2320mm;Coverage:~82% • Pieces: 88 /layer • Thickness: 50mm /layer PMT directly coupled with scintillator

  33. Endcap TOF structure

  34. Bundle of diffuser ... fiber LD Laser fiber Pulse light source system Dark box for R5924-70 Dark box LED HV head PMT R5924 fiber Signal housing Ref. PMT xp2020 HV Signal PMT tests • Gain decrease a factor of 100 @ 1 T • Mass tests finished by Tokyo Univ. and IHEP

  35. Radiation on scintillator Why? It is estimated that the radiation dose of TOF will be about 1000rad/year. Its effects on scintillator need to be test. • Transmission spectrum • Excitation and Emission spectrum • Light yield and its recovery Results : The dose up to 106 rad will damage the scin. Our dose on BESIII is safe enough for scin.

  36. Test beam at IHEP For various types of scintillators, thickness, wrapping materials, … Endcap Barrel

  37. TOF 70±2ps 104±11ps 94±3ps Electron Proton Time resolution from a beam test of the Prototype（including scintillator,PMT, preamp., electronics, cable) PMT and scintillator ordered

  38. Electronic switch Fiber bundles Light splitter TOF endcap 48 fibers TOF endcap 48 fibers Laser TOF barrel 176 fibers TOF barrel 176 fibers fiber PMT connector TDC start Wrapped with steel tube ADC gate fiber Fiber TOF barrel PMT PMT TOF Monitor System • Monitor the amplitude and time performance of each channel including PMTs and electronics. • Being designed by University of Hawaii. approved by DOE: 3/1/2006

  39. TOF electronics test results • Preamp • Rise time:<2ns • Gain：10 • VME • HPTDC: <25ps • QTC: • Trigger Preamp. HPTDC

  40. BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detecor • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  41. Targets of BESIII EMC Measure the energy and spatial information of electron and photon. • Energy region: 20 MeVto 2GeV. key energy region< 500MeV. • Energy resolution: • Spatial resolution: • Reconstruction of 0andη • Contributes to e/ and e/separation • Provide neutral energy trigger

  42. EMC

  43. Mechanical structure • L=28cm ( 15 X0 ) • Pyramid:Front: ~5.0cm x 5.0cmRear: ~6.2cm x 6.2cm

  44. Pipeline of making cells and QC • 30 cells/day Barrel Cell almost finished now.

  45. CsI Calorimeter • Testing: • Size • Source tests (137 Cs) • LED tests • PD tests • Preamp tests • Cosmic ray tests • Beam tests (6 x 6 array): X position ADC

  46. EMC Status A 1/60 prototype Status: • Barrel Assembly machine arrived in the end of Aug. 2006. Barrel Assemblying will begin • By the end of the year, all FED boards should be tested and installed.

  47. EMC electronics • Most preamp. tested and assembled • Noise is about 220 KeV(1000e)/crystal in test beam • Mass production of all electronics boards started • All the electronics boards will be tested and installed by the end of the year

  48. BEPCII status • Progress of BESIII • Physics potential and detector targets • Drift Chamber • Time of Flight • EM Calorimeter • Muon detecor • SuperConducting Magnet • BESIII Trigger, DAQ and offline • Summary

  49. Muon Chamber Barrel + EndCap; RPC as μdetector; Barrel : 9 layers EndCap: 8 layers One dimension read-out strips;

  50. RPC • Plate made from a special type of phenolic paper laminating on bakelite. • Have good surface quality（~200nm). • Extensive testing and long term reliability testing done. • Have high efficiency, low counting rate and dark current, and good long-term stability, low price .

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