1. PID for super Belle (design consideration) K. Inami (Nagoya-u) - Barrel (TOP counter) - Possible configuration - Geometry - Endcap (Aerogel RICH) - Photo detector options - Barrel-Endcap

2. 2 2.6m 1.2m e - 8.0GeV e + 3.5GeV TOP counter Aerogel RICH - PID (  ) detectors - Inside current calorimeter - Use less material and locate near calorimeter  TOP and Aerogel RICH counters - both Cherenkov ring imaging detectors Super B detector

3. 3 TOP counter Quartz: 255cm L x 40cm W x 2cm T Focus mirror at 47.8deg. to reduce chromatic dispersion Multi-anode (GaAsP) MCP-PMT Linear array (5mm pitch), Good time resolution (<~40ps)  Measure Cherenkov ring image with timing information MCP-PMT

4. 4 TOP counter Measure Position+Time Compact detector! Linear array PMT (~5mm) Time resolution  ~40ps ~2m KK Simulation 2GeV/c,  =90 deg. ~200ps Different opening angle for the same momentum  Different propagation length(= propagation time) + TOF from IP works additively.

5. 5 Chromatic dispersion Due to wavelength spread of detected photons, propagation time becomes worse. Longer propagation length  Improve ring image difference But, decrease time resolution.  Optimal propagation length. Light propagation velocity inside quartz Variation of propagation velocity depending on the wavelength of Cherenkov photons

6. 6 Possible configuration Detector type 3-readout type Optimized propagation length Simple configuration  less technical issue Simple ring image  easy reconstruction Focusing type Correct chromaticity 2/3 PMTs Cost Small dead space Easy to replace PMTs because of no middle PMT Complicated ring image Need noble reconstruction method May need more simulation study to check robustness Focus Mirror

7. 7 Possible configuration Photo-cathode of MCP-PMT Multi-alkali Almost established production Enough lifetime GaAsP Better efficiency at longer wavelength Need more production R&D and lifetime test Multi-alkali without Al protection layer on MCP (option) Better efficiency (x1.6) Almost established production, but need some modification to improve lifetime (3-layer MCP, operation with lower gain, etc.) GaAsP MCP-PMT

8. 8 Performance 3-readout type + GaAsP photo-cathode >400nm filter, Correction Eff.=35% 3.5  K/  for 4 GeV/c,  =70 ﾟ

9. 9 Performance Focusing type + GaAsP photo-cathode >400nm filter, Correction Eff.=35% 4.2  K/  for 4 GeV/c,  =70 ﾟ

10. 10 Performance Focusing type + Multi-alkali >350nm filter, Correction Eff.=60% 3.5  K/  for 3 GeV/c,  =70 ﾟ Because of complicated ring image

11. 11 TOP configuration summary Focusing type can reduce the dead space and remove middle PMT. option K/pi separation performance at 70 deg, 4GeV/c critical issues 3 readout + multi-alkali 2.8 sigma(Make prototype) 3 readout + GaAsP 3.5 sigma PMT production PMT lifetime Focusing + multi-alkali 2.5 sigma  4.0 sigma if improved eff. PMT lifetime Focusing + GaAsP 4.2 sigma PMT production PMT lifetime

12. 12 Geometry 18 counters in r-  Al wall (1mm t ) Quartz Similar with BaBar DIRC Narrow space for support structure Only 16mm between quartz bar Gaps in    10% dead space ~1cm weak region from bar edge BaBar DIRC

13. 13 Geometry (2) Possible overlapped layout Need 50cm-width quartz bars (  40cm-width) R1080 of inner radius (  R1150 for previous) Difficulty for support structure Complicated space Need simulation study Requirement from physics Check S/N with    etc. PID performance confirm dead space Effect to outer detector

14. 14 Aerogel RICH Radiator Aerogel (n~1.05) Multiple radiator option Set suitable radiator index By stacking the radiators, Increase N photon without deteriorating ring image Photon detector HAPD, MCP-PMT, MPPC etc. Single photon detection ~400nm Cherenkov photon Operational under ~1.5T magnetic field High hit rate

15. 15 Photon detector option HAPD Good result from test bench with ASIC readout Stability? Need more production R&D MCP-PMT Good TTS for TOF information <20ps TOF resolution Good ability for low momentum PID Need lifetime estimation SiPM/MPPC Good stability, Enough gain and TTS Need large effective area or light guide to make ~5x5mm 2 anode Need gated readout because of high dark count (<~MHz) New Old 20m m MPPC MCP-PMT HAPD

16. 16 Barrel - Endcap Need to minimize dead space TOP needs PMT region at bar end.  We can cover with aerogel radiator. To detect Cherenkov light emitted to outside, we should set mirrors at Aerogel RICH outer cylinder. Simulation study to estimate separation power Some R&D with mirrors PMT Drift chamber Barrel Calorimeter Forward endcap Calorimeter Radiator

17. 17 Summary Photon detector is still main issue for designing. GaAsP/Multi-alkali photo-cathode MCP-PMT for TOP HAPD, MCP-PMT and MPPC with light guide for Aerogel RICH TOP configuration Focusing type + GaAsP photo-cathode MCP-PMT (>4.2  ) Option; Multi-alkali with efficiency improvement Geometry of TOP bars ~10% dead space along  Overlapped TOP geometry  Check requirements from physics Barrel – Endcap Need design study of outer boundary of Aerogel RICH Mirror to correct the out-going Cherenkov photons

18. 18

19. 19 Focusing TOP 1850mm Virtual readout screen 22mm x 5mm matrix Focusing mirror  c ~1.2mrad Use dependence of Cherenkov angle to correct chromaticity Angle information  y position Reconstruct Ring image from 3D information (time, x and y).  c ~1.2mrad over sensitive range   y~20mm (~quartz thickness) We can measure dependence and obtain good separation even with narrow mirror and readout plane, because of long propagation length.

20. 20 Geometry Possible layout with overlap Need 50cm-width quartz bar