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大学 activity: 粒子識別

大学 activity: 粒子識別. 森 隆志 ( 名古屋大学 ) 関西中部地方 B 中間子の物理実験研究会 @ 奈良女子大学 2009 年 11 月 5 日. Contents. Introduction R&D of TOP counter components Performance test of prototype R&D of HAPD for A-RICH counter Summary. 1. INTRODUCTION. 1 . Our Motivation. Upgrade of Belle PID system

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大学 activity: 粒子識別

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  1. 大学activity: 粒子識別 森 隆志 (名古屋大学) 関西中部地方 B中間子の物理実験研究会@奈良女子大学 2009年11月5日

  2. Contents Introduction R&D of TOP counter components Performance test of prototype R&D of HAPD for A-RICH counter Summary 関西中部地方B中間子の物理研究会@奈良女子大学

  3. 1. INTRODUCTION 関西中部地方B中間子の物理研究会@奈良女子大学

  4. 1. Our Motivation • Upgrade of Belle PID system • Current PID system of Belle • π/K – separation power : 3σ • Barrel: TOF + ACC • End cap: ACC Current system • Target Performance • 3σ ⇒ 4σ (0.6 < p < 4 GeV/c) (ACC: Threshold type Aerogel Cherenkov Counter) 1.5T 1.2m Upgrade e- 8.0GeV 2.6m e+ 3.5GeV Install here Belle-II • Barrel: TOP counter • End cap: Aerogel RICH 名古屋大学が中心になって 行っている研究について紹介する Backward Forward 関西中部地方B中間子の物理研究会@奈良女子大学

  5. 2. Principle of TOP counter (1) Imaging with quartz For same momentum, velocity β of π/K is different different ring images Require large screen DIRC(Detection of Internally Reflected Cherenkov light) technique • Cherenkov radiator + screen (photo-detector matrix) • Cherenkov light propagate to terminal of quartz with total reflection • Ring image is detect as parabola 関西中部地方B中間子の物理研究会@奈良女子大学

  6. 2. Principle of TOP counter (2) • TOP(Time Of Propagation) counter • Cherenkov radiator + time sensitive screen • Position (x, y) ⇒ Position + time (x, t) • Very compact & simple TOP TOF 1.18m y TOP counter measures TOF + RICH z x High performance expected! time includes TOF information 関西中部地方B中間子の物理研究会@奈良女子大学

  7. 3. Expected Performance in Belle-II Expected performance cosθ Forward Backward cosθ π/K separation power 4σfor 2<p<4 関西中部地方B中間子の物理研究会@奈良女子大学

  8. 4. Typical Ring image & Key Parameters y Top view ~1000mm z 400mm x π/K t x Detection position & time ~100ps Typical ring image • Key points • Accuracy of quartz radiator ( = lightguide) • Cherenkov light should propagate without distortion and attenuation • Time resolution and sensitivity of photo-detector • To obtain clear ring image • Important parameters : Ndet, 関西中部地方B中間子の物理研究会@奈良女子大学

  9. 5. Requirements to Components Quartz radiator • Propagate Cherenkov light without distortion • Flatness : < 100μm • Right angle accuracy : ~10” • Total reflection for suppression of attenuation • Surface roughness : 5Å Photo-detector • Single photon detection • Gain : ～1.0 ×106 • Important factor of time resolution of TOP counter • TTS : σphotodetector < 40ps • Number of detected photon : ～20 • QE : 20%@λ=400nm • Usable in magnetic field of 1.5T for Belle-II 関西中部地方B中間子の物理研究会@奈良女子大学

  10. 2. R&D OF TOP COUNTER COMPONENTS 関西中部地方B中間子の物理研究会@奈良女子大学

  11. 1. Surface Test of Quartz single photon mirror collimator MCP-PMT prism single photon TTS for each incidence point prism line ① line ② line ③ TTS[ps] MCP-PMT quartz ・407nm pulse laser ・Single photon irradiation ・47.2°incidence propagation length[mm] no degradation of TTS ⇒ sufficiently small roughness 関西中部地方B中間子の物理研究会@奈良女子大学

  12. Channel ~10m ~400m 2. Photo-detector Square type MCP-PMT Co-development with Hamamatsu Photonics Only photo-detector satisfies requirements MCP-PMT (Micro Channel Plate) Channel φ~10μm, Bias angle of MCP : 13° Usable in B-field Requirements • Gain : 1.0×106 • TTS : <40ps • QE : >20%@λ=400nm • Usable in B -field 関西中部地方B中間子の物理研究会@奈良女子大学

  13. 3. MCP-PMT R&D Pedestal Output of single photon Gain ～ 1.0×106 Single photon detection OK Output charge distribution 関西中部地方B中間子の物理研究会@奈良女子大学

  14. 4. MCP-PMT R&D Single photon irradiation 検出時間分布 counts QE[%] σ=34.2±0.4ps QE：24%@400nm transit time [25ps] wavelength [nm] TTS＜40ps OK QE>20%@λ=400nm OK 関西中部地方B中間子の物理研究会@奈良女子大学

  15. 3. PERFORMANCE TEST OF PROTOTYPE 関西中部地方B中間子の物理研究会@奈良女子大学

  16. 1. Beam Test Performed in Jun. & Dec. 2008 Items to confirm • Detection of ring image • Obtain N(), number of detected photons par track • TTSmeasurement Setup of beam test at Fuji test beam line Vetocounter TOP Counter MWPC2 MWPC1 electron beam （2GeV/c） Trigger Counter Timing Counter Beam trajectory MCP-PMT t0 determination Subtract em-shower events 関西中部地方B中間子の物理研究会@奈良女子大学

  17. 2. Result : ring image ④ Ring image (data) Ring image （simulation） ③ ② ① transit time[25ps] transit time[25ps] ch ch Proper action of total system of TOP counter is confirmed 関西中部地方B中間子の物理研究会@奈良女子大学

  18. 3. Result : number of detected photons arbitrary Number of detected photons/events N(γ) consistency confirmed Slightly different ⇒ remaining shower event 関西中部地方B中間子の物理研究会@奈良女子大学

  19. 4. Result : transit time distribution data simulation 1st 3rd 3rd 1st 2nd 2nd カウント数 [photons] ch29 transit time[25ps] transit time[25ps] quartz Beamirradiation point (875mm) 915mm 3rd 2nd 1st 875mm We confirmed consistencyof transit time distributionsfor beam test & simulation 関西中部地方B中間子の物理研究会@奈良女子大学

  20. 1.5T 1.2m e- 8.0GeV 2.6m e+ 3.5GeV Aerogel RICH 4. R&D OF HAPD FOR A-RICH Backward Forward 関西中部地方B中間子の物理研究会@奈良女子大学

  21. 1. Aerogel RICH counter 関西中部地方B中間子の物理研究会@奈良女子大学

  22. 2. HAPD R&D • Hybrid structure • Vacuum tube • APD (5x5mm2 matrix) • Bialkali photocathode • ~104 total gain • Confirmed • Single photon detection • Available in 1.5T B-field • Current issue • Radiation hardness (neutron) study • Photocathode study 73mm 73mm Photo-detection in Magnetic field Single photon irradiation 関西中部地方B中間子の物理研究会@奈良女子大学

  23. 5. Summary & Issues Our Motivation: upgrade of PID system • Target performance: separation power 3σ⇒4σ Idea: barrel ⇒ TOP, end cap ⇒ Aerogel RICH TOP counter • New idea of RICH: Position(x, y) Position(x) + time(=TOF+RICH) • Basic performances are confirmed with prototype • Issue • Structure, reconstruction code, lifetime of PMT, readout, etc… HAPD R&D • Performances are available for ARICH • Issue • Neutron hardness, high QE photocathode study 関西中部地方B中間子の物理研究会@奈良女子大学

  24. BACKUP 関西中部地方B中間子の物理研究会@奈良女子大学

  25. Belle-II experiment Belle detector e+e- asymmetric collider e+ : 3.5GeV e- : 8.0GeV e+e-→ Υ(4S) → BB π/K-ID is important for flavor tagging Higher statistics： Higher luminosity ×~40 B-factory ⇒Super B-factory ＆ Higher accuracy ： Belledetector upgrade Our target of development : Belle-II experiment 関西中部地方B中間子の物理研究会@奈良女子大学

  26. History of R&D Butterfly TOP 関西中部地方B中間子の物理研究会@奈良女子大学

  27. Performance Parameterization Separation power : timing 1m 1m : Difference of TOF +TOPfor π/K（～ 60ps） : Detected photons/track（～20） assumption : TTS of TOP counter : TTS of photo-detector（～40ps） :Chromatic dispersion （1mpropagation in quartz: ～50ps　⇒25ps） Can suppress with λ cut filter Important parameters : Ndet, σphotodetector 関西中部地方B中間子の物理研究会@奈良女子大学

  28. Chromatic Dispersion Typical wavelength distribution of group velocity of light Typical wavelength distribution of detected photons group velocity of light [m/ns] number of detected photons wavelength [nm] wavelength [nm] Restricts TOP TTS This is because refraction index has wavelength dependence Chromatic dispersion 関西中部地方B中間子の物理研究会@奈良女子大学

  29. Suppression of Chromatic Dispersion 350nm Suppression of chromatic dispersion with 350nm wavelength cut filter Group velocity of light σchromatic 50 25ps Number of Cherenkov photons wavelength cut ⇒ TTS improve Transmittance of wavelength cut filter ⇒ fine tune Ndet decrease Wavelength cut 関西中部地方B中間子の物理研究会@奈良女子大学

  30. 1. Radiator Quartz (fused silica) • Size ： 915×400×20 (mm3)‏ • Weight ：16kg • Flatness ： < 1.2μm/m • Surface roughness ：5Å • Refractive index ：1.45 Co-developmentwith Okamotokougaku 関西中部地方B中間子の物理研究会@奈良女子大学

  31. Readout-box PMT Construction of Prototype PMT array with λ cut filter Schematic side view of PMT array Spring loaded polyathetal head plunger×40/surface Distortion of frame is absorbed by spring Al honeycomb 46 mm Quartz 23mm Joint of 2 parts Optical contact : silicon oil + pressure Al honeycomb Cross section of radiator part • Al honeycomb support • Core density：0.037g/cm3 • Thickness ： 10mm • Surface plate ： 0.3mm Al • Sag ：δ < 80μm • Quartz flatness in Frame • <100μm/m (Measured) 関西中部地方B中間子の物理研究会@奈良女子大学

  32. AMP+CFD amp comparator to TDC to ADC input low voltage supply PMT module • HV divider + AMP + Discriminator • Small size (28mmW) • Prototype • Fast AMP (MMIC, 1GHz, x20) • Fast comparator (180ps propagation) • CFD with pattern delay • Performance • Test pulse • ~5ps resolution • MCP-PMT • s<40ps • Working well 関西中部地方B中間子の物理研究会@奈良女子大学

  33. 2. Performance Confirmation by Beam Test Items to confirm • Detection of the ring image of the Cherenkov light • Obtain N(), the number of detected photons par track • Measure the TTS MC simulation Ring image • Number of detected photons • Ndet = 16 • TTS for 1st surface of ring image • = 78 [ps] transit time[25ps] ch • Demonstration of the TOP counterwith MCP-PMT array 関西中部地方B中間子の物理研究会@奈良女子大学

  34. Set up for Beam Test Quartz + MCP-PMT Fuji test beam line at KEK TOP Counter MWPC② y y electron beam （2GeV/c） Trigger Counter Timing Counter x x MWPC① Beam trajectory Vetocounter MCP-PMT t0 determination Subtract em-shower events 関西中部地方B中間子の物理研究会@奈良女子大学

  35. TTS of timing counter counts σ=13.4±0.7ps transit time[25ps] 関西中部地方B中間子の物理研究会@奈良女子大学

  36. 伝播距離によって時間分解能はどれだけ悪化するか？伝播距離によって時間分解能はどれだけ悪化するか？ 波長分散効果を考慮した理解は正しいのか？ シミュレーション 時間分解能[ps] 伝播距離 [mm] 各伝播距離における測定結果が シミュレーションを再現 波長分散効果が予想通り のものであることを確認 関西中部地方B中間子の物理研究会@奈良女子大学

  37. 関西中部地方B中間子の物理研究会@奈良女子大学関西中部地方B中間子の物理研究会@奈良女子大学

  38. Summary for TOP Counter TOP counter is very compact & simple detector based on TOF + RICH technique • Radiator propagates Cherenkov light without distortion • Position(x, y) Position(x) + time (= TOF + TOP) Target performance of TOP counter • >4σfor 0.6 < p < 4GeV/c • Key parameters • Number of detected photons Prototype of TOP counter has been constructed • We confirmedbasic performancesof prototype withfollowing parameters: 関西中部地方B中間子の物理研究会@奈良女子大学

  39. 関西中部地方B中間子の物理研究会@奈良女子大学関西中部地方B中間子の物理研究会@奈良女子大学

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