Aerogel RICH & TOP counter for super KEKB Y.Mazuka Nagoya University
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Aerogel RICH & TOP counter for super KEKB Y.Mazuka Nagoya University June 14-16, 2006 The 3rd SuperB workshop at SLAC Introduction Current BELLE performance We cannot PID at high momentum region in the forward endcap Present endcap-ACC is used only for flavor tagging Further Improvement on p/K separation with the start of super KEKB PID Target: p/K separation > 4s @4GeV/c June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 2/24 Upgrading BELLE Detector Two new particle ID devices, both RICHes Inside of BELLE detector e- e+ Endcap: Proximity Focusing Aerogel RICH(A-RICH) Barrel: Time of Propagation Counter(TOP) June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 3/24 Outline Photon detectors R&D HAPD MCP-PMT Optical improvement Focusing radiator New idea RICH w/ TOF A-RICH Optimize parameters Basic principle TOP MCP-PMT R&D aging Operation in B field Photo-cathode study GaAsP Basic design June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 4/24 c Charged particle Photon detector Endcap: Proximity Focusing A-RICH A-RICH • PID by Cherenkov ring image emitted from aerogel radiator • Cherenkov angle p/K (4GeV/c, n=1.05) cp cK 23mrad aerogel Angle distribution # of detected photons Typical beam test results p-, 4GeV/c, 2cm thick aerogel p/K separation ~ 4.0s It seems to reach our target, but NIM A553(2005)58-63 June 14-16, 2006 Can we improve the separation over 4s? The 3rd SuperB workshop, SLAC Y.Mazuka 5/24 Focusing configuration A-RICH How to increase the number of photons without degrading the resolution? Use radiator with gradually increasing refractive index in down stream direction Normal configuration n 1 = n2 n1 n2 Focusing configuration n 1 < n2 n1 n2 June 14-16, 2006 Photon detector Photon detector aerogels aerogels The 3rd SuperB workshop, SLAC Y.Mazuka 6/24 Results of focusing configuration 4cm thick aerogel normal n=1.047 sc=22.1mrad Npe=10.7 much configuration p/K separation with focusing 2 layers of 2cm thick n1=1.047, n2=1.057 focusing A-RICH better! ~ 4.8s @4GeV/c much clearer! sc=14.4mrad Npe=9.6 NIM A548(2005)383 June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 7/24 Optimization of dual radiator indices Upstream aerogel: n1=1.045 Downstream aerogel: n2 is changed A-RICH Data points: Dec. 2005 beam test physics/0603022 fixed expectation n2-n1 Measured resolution is in good agreement with expectation Wide minimum region allows some tolerances(~0.003) in aerogel production June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 8/24 Outline Photon detectors R&D HAPD MCP-PMT Optical improvement Focusing radiator New idea RICH w/ TOF A-RICH Optimize parameters Basic principle TOP MCP-PMT R&D aging Operation in B field Photo-cathode study GaAsP Basic design June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 9/24 Photon Detectors for A-RICH A-RICH • Requirements – Working in B=1.5T – Pixel size ~5-6mm – Good sensitivity to single photon – Large effective area • Candidates – HAPD with large effective area – MCP-PMT June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 10/24 Photon Detectors for A-RICH; demerits ~-10kV A-RICH merits – Low gain (~104) – High noise rate multi-alkali Photo-cathode HAPD photon – High efficiency – High energy resolution HAPD prototype design e- Pixel APD Good sensitivity to single photon Problems Now studying with HPK! difficulties of sealing activation of photocathode changes the properties of APD June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 11/24 Photon Detectors for A-RICH; MCP-PMT A-RICH BURLE 85011 MCP-PMT photocathode Bi-alkali MCP 25mm pores, 2 MCPs gain ~ 0.6×106 collection efficiency ~ 60% demerit active area dimensions ~ 71mm square # of channels 8×8 pitch ~ 6.45mm active area ~52% June 14-16, 2006 merits High gain Good time resolution TTS~50psec(single p.e.) Can we use this merit? The 3rd SuperB workshop, SLAC Y.Mazuka 12/24 A-RICH with TOF using MCP-PMT New idea! Fast photon detector enables A-RICH to have TOF info. MCP-PMT Concept in Belle detector aerogel p/K 4GeV IP 1.8m Cherenkov photons emitted in the 0.2m Cherenkov lights from PMT window DTOFring(p/K) ~37psec Aerogel radiator PMT glass window DTOFwindow(p/K) ~47psec @4GeV/c TTS of BURLE MCP-PMT can reach 19 psec for multi photons STOF (p/K) > 2.4σ for multi photons? PID can extend lower momentum region DTOF(p/k) is bigger June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 13/24 A-RICH with TOF Beam test results A-RICH Read 13 channels PMT window hit point ring image point • TTS(ring image point) ~50psec – Time resolution per one track (Npe~10) ~20psec • TTS(PMT window hit point) ~37psec Consistent to expectations p/K separation with MCP-PMT STOF ~ 2.2s @4GeV/c June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 14/24 A-RICH with TOF PID at low momentum A-RICH TOF test with pions and protons at 2GeV/c Photons from PMT window p/p are well separated Even in distance between start counter and MCP-PMT is 65cm, instead of 2.0m in Belle At this test, p/p separation with MCP-PMT STOF ~ 4.8s @2GeV/c June 14-16, 2006 The 3rd SuperB workshop, SLAC A-RICH with TOF using MCP-PMT looks very promising Y.Mazuka 15/24 Outline Photon detectors R&D HAPD MCP-PMT Optical improvement Focusing radiator New idea RICH w/ TOF A-RICH Optimize parameters Basic principle TOP MCP-PMT R&D Operation in B field aging Photo-cathode study Basic design June 14-16, 2006 The 3rd SuperB workshop, SLAC GaAsP Y.Mazuka 16/24 Barrel: TOP counter TOP Cherenkov ring imaging is used as timing information Difference of path length Difference of time of propagation (TOP) (+ TOF from IP) With precise time resolution (s~40ps) June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 17/24 Photon Detector for TOP; MCP-PMT Requirements: TOP 3 MCP-PMTs studied: Good sensitivity to single photon TTS~30ps (single photon) working in 1.5T BURLE (25mm pores) BINP (6mm pores) HPK (6 and 10mm pores) B=0T: all samples have good TTS(~30ps) B=1.5T: BINP and HPK samples have high gain(~106) and good TTS(~30ps) NIM A528 (2004) 763 These samples were round shaped (1ch.) We’ve developed square shaped (4ch.) June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 18/24 MCP-PMT aging TOP Study of tubes w/ and w/o Al layer Photo-cathode: multi-alkali Prevent feedback ions from reaching the photo-cathode (It reduces collection efficiency by 60%) HPK w/ Al survives over 13 years of operation! Al layer is necessary June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 19/24 MCP-PMT with GaAsP TOP Expected performance bialkali photo-cathode: p/K separation at 4GeV/c < 4s chromatic dispersion Light velocity in quartz GaAsP photo-cathode: Higher Q.E. At longer wavelength →less dispersion p/K separation > 4s @4GeV/c June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 20/24 GaAsP MCP-PMT development TOP • Square-shape MCP-PMT with GaAsP photocathode is under development with HPK • First prototype – The same type as previous tubes • Performance test – Gain – Time resolution CAMAC 36dB PLP PMT ATTN AMP DISC there 100mV DISC BLACK BOX The 3rd SuperB workshop, SLAC ADC GATE λ=407nm FILTER Jitter～10ps June 14-16, 2006 DIV Y.Mazuka 25ps/1bin TDC there 20mV START 21/24 GaAsP MCP-PMT performance TOP Wave form, ADC and TDC distributions pedestal TTS～35ps single photon peak Single p.e. 0.5ns/div 20mV/div Gain～ 0.64×106 Enough gain(~106) to detect single p.e. Good time resolution (TTS~35ps) for single p.e. Next Check the performance in detail Life time of GaAsP photo-cathode tube June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 22/24 Summary We are studying new types of RICH for super KEKB Aerogel RICH counter for endcap - Test the focusing configurations • We studied about optimal parameters - More studies: RICH with TOF (using MCP-PMT) • Extend PID ability into low momentum region TOP counter for barrel 6,TTS~30ps) - MCP-PMT operation in 1.5T is look OK (Gain~10 Both RICHes(A-RICH, TOP) very promising separation can beisover 4s @4GeV/c - Al protectp/K layer for MCP-PMT effective to keep QE - MCP-PMT GaAsP But therewith is still a lot of work to be done! • Enough TTS ~35ps • It will reduce the effect of chromatic dispersion June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 23/24 Tasks for practical use A-RICH – Photon detectors • Develop HAPD & MCPPMT in parallel – Readout system TOP – MCP-PMT • ASIC – Mechanical design • Line up of photon detectors and radiators • Make practical tube • Aging of tube with GaAsP – Readout system TAC – Test of prototype • Line up of photon detectors and radiators June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 24/24 Backup June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 25/24 Optimal aerogel thickness Cherenkov angle resolution per track s track sc N pe The best resolution ~ 5.5mrad at 2cm thick aerogel June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 26/24 RICH with TOF RICH with TOF ΔTOP(K-π) ～-5psec (Difference of TOP from emission point of Cherenkov light to PMT) ΔTOF1(K-π) ～42psec R Aeroｇel 4GeV IP 1.8m 0.2m G ⊿TOFR ～37psec ⊿TOFG ～47psec Cherenkov photons generate in glass ΔTOF2(K-π) ～47psec (Difference of TOF from IP to PMT) PMT Time resolution of 10 psec has been achieved with HPK MCP-PMT @ Nagoya university. Time resolution of BURLE MCP-PMT can reach 19 psec for multi photons. More than 2.4σ for multi photons? June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 27/24 A-RICH with TOF using MCP-PMT A-RICH Setup of beam test MCP-PMT BURLE 85011 Start counter MCP-PMT TTS~10ps quartz June 14-16, 2006 MWPC Aerogel MWPC Beam Cherenkov photons from PMT window The 3rd SuperB workshop, SLAC Trigger counters Y.Mazuka 28/24 K/p separation by TOF Good performance in lower momentum region Enable PID under threshold Pc of aerogel ●ring image point ▼glass hit point Threshold SEPARATION POWER(s) S(K/p) > 10s MOMENTUM(GeV/c) June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 29/24 TOP counter MC Expected performance bi-alkali photocathode: p/K separation at 4GeV/c < 4s (because of chromatic dispersion) Light velocity in quartz GaAsP photocathode: p/K separation at 4GeV/c > 4s less dispersion June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 30/24 TTS 30ps June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 31/24 Cross-talk of MCP-PMT SL10: cross-talk problem solved by segmenting electrodes at the MCP June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 32/24 R&D of Readout ASIC for TOP Time-to-Analog Converter Time resolution <~20ps Double overlap gates Less dead time (~100ns) 0.35m CMOS process 2nd batch TAC-IC was submitted to VDEC (U. Tokyo) INPUT 125ps GATE1 T1 75ps GATE2 T2 AOUT1 V1 = K x T1 V2 = K x T2 AOUT2 40MHz CLOCK June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 33/24 Readout Electronics Aerogel RICH readout Total ~ 100k channels! Readout scheme pipeline Only record hit information Basic parameters for the ASIC CMOS-FET Gain=10V/pc Shaping time=0.15msec VGA=1.25~20 18 channels/chip Power consumption : 5mW/channel Preamp Shaper June 14-16, 2006 VGA □4.93[mm] 3rd batch was submitted to VDEC (More protection to noise was done ) Comparator The 3rd SuperB workshop, SLAC Shift register Y.Mazuka 34/24 Design • Quartz: 255cmL x 40cmW x 2cmT – cut at =46deg. to reduce chromatic error • Multi-anode MCP-PMT – Linear array (5mm pitch), Good time resolution (<~40ps) – Three readout plane Forward θ June 14-16, 2006 The 3rd SuperB workshop, SLAC Need 18 Quartz units, 4320 MCP channels Y.Mazuka 35/24 Mechanical design Aerogel Photo detector • Aerogel radiator – Hexagonal tiling to minimize aerogel boundary – side length, 125 mm • Photo detector – Total PD : 564, 6 sectors – Cover 89.0% of area June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 36/24 Collaborator I.Adachi, K.Fujita, A.Gorisek, T.Fukushima, D.Hayashi, T.Iijima, K.Inami, T.Ishikawa, H.Kawai, Y.Kozakai, P.Krizan, A.Kuratani, T.Nakagawa, S.Nishida, S.Ogawa, T.Ohshima, R.Pestotnik, T.Seki, T.Sumiyoshi, M.Tabata, Y.Unno June 14-16, 2006 The 3rd SuperB workshop, SLAC Y.Mazuka 37/24
