Focusing Aerogel RICH for PID and Momentum Measurement A.Yu.Barnyakov, M.Yu.Barnyakov, V.S.Bobrovnikov, A.R.Buzykaev, V.V.Gulevich, S.A.Kononov, E.A.Kravchenko, A.P.Onuchin Budker Institute of Nuclear Physics, Novosibirsk, Russia A.F.Danilyuk Boreskov Institute of Catalysis, Novosibirsk, Russia Presented by E.A.Kravchenko

E.A.Kravchenko, "FARICH for PID and momentum measurement" Outline RICH with aerogel and additional high refractive index radiator FARICH for SuperB Factory detector FARICH for Super Charm-Tau Factory detector at Novosibirsk FARICH prototype and test beam line for detector R&D Conclusion May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" Why Aerogel? The difference of Cherenkov angles for different particles is larger Dispersion is smaller The large number of detected photons from high refractive index radiators can not compensate these effects (~ 1/√Npe) May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Aerogel disadvantages Low light ~(1-1/n2) 6 times smaller than in quartz (for n=1.05) Close to 100% light collection needed High threshold Pth=m/√n2-1 => additional high refractive index radiator (water, NaF or others) threshold counter mode AEROGEL NaF May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" SuperB Factory in LNF Crab-waist scheme, L=1036cm-2s-1 e- longitudinal polarization Collaboration expect government approvement in the nearest future Damping ring Detector hall May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" SuperB detector TOFlike PID Wide use of BaBar ideas, parts and experience Serious work on detector geometry optimization Several PID options in the forward May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" FARICH for SuperB Expansion gap 180 mm Burle MCP PMT with 6x6 mm pixels (8x8 matrix), photoelectron collection efficiency 70%, geometrical factor 70% 3-layer focusing aerogel, nmax=1.07, total thickness 40 mm, NaF radiator, n=1.33, 10 mm thickness Number of PMTs ~ 320 Number of channels ~ 20000 Amount of material, (X0) = 4%(aerogel)+ 10%(NaF)+ 14%(MCP PMT)+8% (support, electronics, cables) ~ 35% May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

FARICH expected performance (MC results) [normal incidence, B = 0.T, MS off] Npe = 17+32 σβ/β ≥ 8·10-4 additional effects of resolution degradation (Pπ=0.7GeV/c, βγ=5) B=1.5T, MS off 0.1% B=0. T, MS on 6% B=1.5T, MS on B=1.5T, MS off, dip angle 13° 18% B=1.5T, MS on, dip angle 13° 32% May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Super Charm-Tau Factory project at BINP (Novosibirsk) Crab-waist scheme, L=1035 cm-2s-1 e- longitudinal polarization E at c.m. from 2 to 5 GeV Infrastructure partly exists (injector, part of tunnels) Very close link in accelerator development with SuperB project May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Super Charm-Tau detector Standard set of subsystems (1-Vertex Detector, 2 – Drift Chamber, 3 – PID => FARICH, 4 – EMC, 5 – Superconducting Solenoid, 6 – IFR) Very promising signals from last contacts with Russian government for this project May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Physics motivation for PID system “golden” process is the search for lepton flavor violation in τ decays: τ→μγ (projected sensitivity Br ≤ 10-9) main background is τ→ππ0ν (Br = 25%) muon tagging of τ decays doubles tagging efficiency powerful μ/π separation is needed below 1 GeV/c (pion supression at the level 100 or better, muon system can not provide this) =>This task is accessible only with a FARICH May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

FARICH for Super Charm-Tau detector 4π geometry 20 m2 of radiator and photon detectors focusing aerogel 106 channels SiPMs are the main candidate for the photon detector (gas filled photo-detectors with bialkali photo-cathode could be a cheap alternative?) May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Monte Carlo simulation Expansion gap 200 mm Photon detector: Hamamatsu MPPC 3x3 mm, pitch 4.1 mm (fill factor 53%) Radiator: 4-layer aerogel, (optimal focusing at Pπ=1 GeV/c) , nmax=1.07, total thickness 35 mm Npe ≤ 23 σβ ≥ 4·10-4 May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Monte Carlo simulation σP/P=γ2·σβ/β σP/P≥ 1% May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" FARICH prototype box designed for radiator-PD distance from 50 to 700 mm 32 MRS-APDs (SiPMs) as photon detectors custom made discriminator boards CAEN V1190B 64 channel multihit TDC May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" Prototype status All SiPMs are tested (amplification, noise rate) Tests of boards with discriminators are in progress Tests with photo-diode are in progress All components are available, assembly is in progress The first beam tests in October 2010 May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Test beam at VEPP-4M, Novosibirsk Emaxbeam = 5.5 GeV Moving converter will be put in the beam halo to produce bremstrahlung gammas Gamma-quanta are converted to electron-positron pairs in the target. Magnet is used to select electrons (positrons) with the required energy. May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" Test beam apparatus Magnet Coordinate chambers Veto and trigger counters NaI calorimeter FARICH prototype May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Experimental hall with beam line components supports May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Two coordinate movement system with remote control May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

Trigger and Veto scintillation counters NaI calorimeter May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" Drift chambers May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" Conclusion FARICH with additional NaF radiator is suggested for PID in the forward part of SuperB detector. FARICH suggested for the Super Charm-Tau factory detector must provide exceptional level of particle identification. The construction of the FARICH prototype and test beam facility is on the final stage. First experiments are foreseen at the end of 2010. May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"

E.A.Kravchenko, "FARICH for PID and momentum measurement" MRS APD parameters Producer - Center of Perspective Technology and Apparatus – CPTA, Moscow http://www.spta-apd.ru/ Genuine name - MRS APD (other names: silicon photomultiplier, PPD,MPPC…) 2.1x2.1 mm sensor 4x4 mm case size PDE=40% @ 600 nm Gain ~ 4·105 Time resolution ~100 ps Dark counts ~10 MHz (0.5pe threshold) May 3-7, 2010 E.A.Kravchenko, "FARICH for PID and momentum measurement"