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Highlights from RICH2007

Highlights from RICH2007. PPD Seminar. S.Easo, A.Papanestis, S.Ricciardi. Contribution from S.Easo. 28-11-2007. Outline. RICH detectors in accelerator based experiments:. Review of Advantages and Limitations of RICH for PID. R&D for new RICH systems.

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Highlights from RICH2007

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  1. Highlights from RICH2007 PPD Seminar S.Easo, A.Papanestis, S.Ricciardi Contribution from S.Easo 28-11-2007

  2. Outline • RICH detectors in accelerator based experiments: • Review of Advantages and Limitations of RICH for PID • R&D for new RICH systems • Historical Overview: 1900 (Marie & Pierre Curie) 1934-44 P.Cherenkov + Frank + Tamm 1960 Arthur Roberts : First Proposal for RICH 1976 T. Ypsilantis + J. Seguinot : Pioneering the construction of the first RICH

  3. RICH design: Basics For momenta well above threshold p/K separation-limiting case Refractive Indices n=1.474 (Fused Silica) n=1.27 (C6F14 CRID) n=1.02 (Typical Silica Aerogel) n=1.001665 (C5F12/N2 CRID Mix) n=1.0000349 (He) s[qc(tot)] u l n ▲ 2 mrad 1 mrad 0.5 mrad 0.1 mrad • N s optimization is not the whole story: One needs to minimize the misID rate and maximize the Positive ID efficiency. • Sources of misID includes interactions, particle decays, physics effects in other parts of the detector etc. B.Ratcliff

  4. Detectors-Photon Detection and Radiator Thresholds • Aerogel: Rayleigh scattering  Low effective transmission at low wavelengths B.Ratcliff

  5. RICH Imaging-Limits to Performance • N pe : More Photons are better, but limited by the technology available. • Larger bandwidth rapid increase in chromatic error • C : Need excellent tracking detector and control of alignment systematics • Physics Limits: overall performance for the event limited by decays and interactions. • Single photon resolution: + • Examples of performances shown in the following slides. • Many choices available for tuning the performance. B.Ratcliff

  6. Types of RICH Detectors: Current/Near Future D.Websdale

  7. Discussion: Why RICH is not used in General Purpose Detectors at LHC, ILC: Large Momenta Low Refractive Index Gas Radiators of Length 1 to 2 meters. Increase the size and hence cost, of calorimeter & muon detectors, downstream of a RICH D.Websdale

  8. RICH covers the large Momentum range 1-100 GeV/c : using three radiators: Aerogel, C4F10 and CF4.

  9. LHCb-RICH • Pioneered the use of HPDs: 1024 pixels per tube bump bonded to readout chip and encapsulated in the vacuum tube. HPDs in RICH2 • RICH2 installed and ready for global commissioning. • RICH1: Major parts installed. Photodetectors ready to mount on RICH1.

  10. Example of LHCb-RICH PERFORMANCE • Performance as seen in Simulated Data in 2006 • Yield: Mean Number of hits per isolated • saturated track (Beta ~1). Single Photon Cherenkov Angle Resolutions in mrad. • Chromatic: From the variation in • refractive index. • Emission Point: Essentially from the • tilt of the mirrors. • Pixel Size: From the granularity of the • Silicon detector pixels in HPD • PSF ( Point Spread Function): • From the spread of the Photoelectron direction • as it travels inside the HPD

  11. LHCb RICH LHCb RICH PID Performance B0sDs-K+B0sDs- p+ (signal)(background) After using RICH, background at 10% level from 10 times level

  12. BABARDIRC: PERFORMANCE • DIRC measures J. Schwiening • DIRC Performs as per design: p/K separation in 0.54 GeV/c

  13. DIRC Upgrade: Focusing DIRC for Super B Factory • Prototype tests made with 6 X 6 mm Hamamatsu H8500 flat panel MAPMT (sTTS=140 ps), Burle 85011 MCP-PMT( sTTS = 50-70 ps), 3 X 12 mm Hamamatsu H9500 Flat panel PMT ( s TTS =220ps). J. Schwiening

  14. DIRC Upgrade: Expected Performance / Lpath=10 m Npe = 28 for 1.7 cm quartz / J. Schwiening

  15. BELLE Upgrade: Super B Factory P.Krizan • Beam Tests done with 2cm thick Aerogel tiles and H-8500 Flat panel MAPMT: • Details in NIMA 553 (2005) 58 • Single photon resolution: 15 mrad, Npe = 6. This yields a 4 s K/p separation • The photon detector does not work in Magnetic field

  16. BELLE Upgrade: Proximity Focusing RICH T.Iijima, P.Krizan • Other Photon detector options for 1.5 T field: • To increase the yield: increase the thickness of aerogel or use aerogel tiles as multiple radiators. sc=22.1mradNpe=10.7 Conventional 4cm thick aerogel n=1.047 sc=14.4mradNpe=9.6 Multiple Radiators 2 layers of 2cm thick n1=1.047, n2=1.057 p/K separation with focusing configuration ~ 4.8s @4GeV/c

  17. BELLE Upgrade: Super B factory H.Haba, S.Korpar • Tests done with aerogel radiator producing Cherenkov photons from a cosmic ray setup and Hamamatsu SiPM

  18. RICH with Gas based photodetectors • CLEO-c Experiment : Charm Physics at CESR : p /K separation up to 3 GeV/c . LiF radiator with 20 m 2 of CH4+TEA in MWPC. • ALICE experiment: • Physics of Strongly interacting matter, QGP • in nucleus-nucleus collisions at LHC. • p /K separation in 1 5 GeV/c • 11 m2 of CSI photocathode • gain < 10 5 • Ready to take data • At high event rates the gain is limited by the photon and ion feed back problems. L.Molnar

  19. ALICE Upgrade: Simulation • New version of gas based detectors are being developed: GEM detectors : 0.31.6 ns readout time. • ALICE: • Simulation: Mirror ROC 240 cm, Photons focusing on a plane at ROC/2. p K p G.Volpe Result of ALICE upgrade simulation

  20. R.Chechik Gas based Detectors GEM • PHENIX: Identify electron pairs coming from relativistic heavy ion • collisions at sqrt(s)= 200 GeV for Au-Au. • Background from charged hadrons, electron-positron pairs from • g conversions and p 0 Dalitz decays in the invariant mass • range < 1GeV/c2 • HBD features: No windows: Photons create blobs of hits in the GEM • Hadron Blind: Hadrons produce only ionization signal which • are then suppressed.

  21. Summary • The field of RICH detectors is still evolving. Several new detectors are ready to • take data or are planned to be constructed. • New types of photodetectors: Flat Panel PMTS, Silicon photomultipliers and GEMs • have the potential to improve the performance of the next generation of RICH detectors. • Novel Detector configurations like Focusing DIRC, Focusing Aerogel tiles • can also enhance the performance of the RICH systems.

  22. EXTRA SLIDES

  23. COMPASS UPGRADE F.Tessarotto • Spin structure of the nucleon, gluon polarization • Open charm produciton leading to D mesons. D0  K - p + • At high rates, lot of background hits seen • in the very forward region in MWPC. • Expected increase in trigger rate 20100 kHz • Replace the central region with MAPMT

  24. COMPASS Upgrade F.Tessarotto

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