RICH simulation for CLAS12 Contalbrigo Marco INFN Ferrara Luciano Pappalardo INFN Ferrara Hall B Central Detector Forward Detector M. Contalbrigo1JLAB12 coll. Meeting 18 Nov 09 RICH detector Substitute 2 LTCC sectors with a proximity RICH detector 3 cm 80 cm GeV /c /K TOF LTCC HTCC /p TOF LTCC HTCC K/p TOF LTCC ratio K/ ~ M. Contalbrigo2JLAB12 coll. Meeting 18 Nov 09 Simulation with realistic phase space To detemine the best photon detector size, ,K,p have been generated at the LTCC-RICH entrance window according with a realistic phase space distribution of reconstructed momenta and angles. (GeV/c) M. Contalbrigo3JLAB12 coll. Meeting 18 Nov 09 UV light Hall-A approach Multiwire chambers (with CSI) suitable as cheap photon detector of large area M. Contalbrigo4JLAB12 coll. Meeting 18 Nov 09 Old GEANT3/Fortran/PAW based MonteCarlo framework the same used the for the development of the Hall A Proximity RICH but with different geometry and size! Charged particles phase space at the LTCC-RICH entrance window from CLAS simualtion, same distribution for ,k,p Use arcs as radiator and detector geometries (see next) Limitation on photon production (~3000) old memory constraint. This becomes relevant for radiator thickness > cm Main output parameter: k = mean error on Cherenkov angle reconstruction of k and Monte Carlo studies: framework CC CKCK K- = ( K + )/2 M. Contalbrigo5JLAB12 coll. Meeting 18 Nov 09 Points: MonteCarlo, Curves: analytical functions ~ 1 mr difference C 5 F 12 mandatory! Geometry from the previous example Radiator Type for UV light C 5 F 12 C 6 F 14 CC CC nn M. Contalbrigo6JLAB12 coll. Meeting 18 Nov 09 Typical spectrum for a generic PM 1/100, 90 % eff 1/100, 75 % eff M. Contalbrigo7JLAB12 coll. Meeting 18 Nov 09 UV light Hall-A approach Multiwire chambers (with CSI) suitable as cheap photon detector of large area C 6 F 14 has not enough discrimination power at large momenta C 5 F 12 is technologically challenging: liquid only below 29 o needs 0 o to keep same vapor pression of C 6 F 14 M. Contalbrigo8JLAB12 coll. Meeting 18 Nov 09 Idea: why not visible light with C 6 F 14 ? Much reduced cromatic error Longer absorption length -> higher number of p.e. Higher cost due to photomultiplers Higher material budget before ECAL M. Contalbrigo9JLAB12 coll. Meeting 18 Nov 09 Simulation based on most conservative n (Moyssdes) M. Contalbrigo10JLAB12 coll. Meeting 18 Nov 09 Quartz absorption length and refraction index from Khashan and Nassif, Optic communications 188 (2001) 129 M. Contalbrigo11JLAB12 coll. Meeting 18 Nov 09 Typical spectrum for a generic PM M. Contalbrigo12JLAB12 coll. Meeting 18 Nov 09 Accounting in addition for 0.65 efficace detection efficiency M. Contalbrigo13JLAB12 coll. Meeting 18 Nov 09 C 6 F 14 C 5 F 12 No improvement at a variance with expectations: Reduced chromatic error (uniform refr. Index) Increased photon number (larger abs. length) M. Contalbrigo14JLAB12 coll. Meeting 18 Nov 09 C 6 F 14 C 5 F 12 M. Contalbrigo15 No difference in the Cerenkov angle resolution JLAB12 coll. Meeting 18 Nov 09 C 6 F 14 C 5 F 12 Vs. track angle Vs. photon energy M. Contalbrigo16JLAB12 coll. Meeting 18 Nov 09 Vs. emission point M. Contalbrigo17JLAB12 coll. Meeting 18 Nov 09 Particle impact point z fixed at -5 cm (before freon) move z to 0 cm (freon surface) M. Contalbrigo18JLAB12 coll. Meeting 18 Nov 09 Vs. emission point M. Contalbrigo19JLAB12 coll. Meeting 18 Nov 09 Vs. track angle Vs. photon energy M. Contalbrigo20JLAB12 coll. Meeting 18 Nov 09 Cerenkov angle resolution improves and now scales as expected with UV vs VISIBLE light M. Contalbrigo21JLAB12 coll. Meeting 18 Nov 09 C 6 F 14 C 5 F 12 M. Contalbrigo22JLAB12 coll. Meeting 18 Nov 09 Assume: Two radiators (only 1 simulated); one per sector Detector covers up to 2 sectors (detect photons from both radiators) Radiator Polar acceptance: 5 30 fix radiator size ~ 4 m 2 Max gap length = 120 cm Not to scale Unit: mm and degree M. Contalbrigo23JLAB12 coll. Meeting 18 Nov 09 55 25 35 20 90 freon Quartz (0.5cm) gap beam line O A B A B K C C H H Space for support and neoceram ? Minimum radius fixed by 5 o requirement ? How to define maximum radius ? Study gap depth and freon thickness M. Contalbrigo24JLAB12 coll. Meeting 18 Nov 09 M. Contalbrigo25JLAB12 coll. Meeting 18 Nov 09 C 6 F 14 with visible light: similar or better than C 5 F 12 Pad size 2 cm Pad size 0.6 cm Pad size 0 cm M. Contalbrigo26JLAB12 coll. Meeting 18 Nov 09 Hamamatsu R7400-U03: 18 mm diam., 12 mm length 0.8 x 0.8 cm 2 pixel, 50 % packing density Spectral range nm, max q.e. at 420 nm ~0.1 keu each: 1 m 2 costs about 250 keuro Hamamatsu H8500/H9500: 52 mm square. 0.6 x 0.6 cm 2 pixel, 89 % packing density Spectral range nm, 25 % q.e. at 420 nm ~1.5 keu each: 1 m 2 costs > 500 keuro Hamamatsu R M16: 26 mm square. 0.5 x 0.5 cm 2 pixel, 50 % packing density Spectral range nm, max q.e. at 420 nm ~0.5 keu each: 1 m 2 costs about 700 keuro 2