1 Efficient trigger for many B decay topologies Muon System CALORIMETERS PRS + ECAL+ HCAL RICH1 VERTEX LOCATOR Efficient PID Good decay time resolution Magnet Good tracking and mass resolution RICH2 Trigger Tracker Inner and Outer Trackers Inner and Outer Trackers Beam 1 Beam 2 2 cm 2 s cm 2 s cm 2 s -1 LS1 LS2 3fb 7 TeV 5-7 fb fb 14 TeV 50 ns 25 ns 1 MHz 40 MHz L L Beam Energy Bunch Spacing L0 rate After LS2, High occupancy in the central region requires new detectors technology and granularity Silicon detectors with embedded r-o electronics must be replaced After LS2, High occupancy in the central region requires new detectors technology and granularity Silicon detectors with embedded r-o electronics must be replaced 4 2 x ~3 m 2 x ~ 2.5 m readout Silicon strips Straw Tubes Scintillating Fibers + SiPM (An hybrid version combining Scintillating fibers and Straw Tube is also considered) 3 stations of X-U-V-X scintillating fibre planes (5).=> 12 planes Every plane is made of 5 layers of 250 m fibres, 2.5 m long. Symmetry around y=0 Read out by SiPM outside acceptance Minimize the dose to read-out electronics and dead materials in the acceptance. 5 Npe SiPM array 1 SiPM channel Resolution (c.o.g.) um Double cladded scint. fibres, e.g. Kuraray SCSF-78, 250 um 6 Scintillating Fibers and SiPM already been used in HEP but: not for read out of 2.5m SciFi not in high radiation environment. Main Challenges Radiation hardness of SiPM (increase of dark current with radiation) Radiation hardness of Fibers (decrease of light yield and attenuation length) LHC environment (25 ns), high occupancy and background Detector geometry and integration in existing experiment. 7 Max dose to fibers 35 kGy (err 8%) Dose distribution strongly peaked around the beam pipe Dose to the SiPM: ( MeV n eq) Max dose to fibers 35 kGy (err 8%) Dose distribution strongly peaked around the beam pipe Dose to the SiPM: ( MeV n eq) FLUKA simulation for 50 fb-1 integrated luminosity Gy/collision 8 Irradiation performed at CERN and Karlruhe, up to ~60k Gy Attenuation length decreases with absorbed dose Logarithmic dependence (effect observed already at low dose) Attenuation length decreases with absorbed dose Logarithmic dependence (effect observed already at low dose) 9C. Joram / CERN9 Reflectivity Aluminized mylar foil 3M ESR foilAluminium thin film coating Two samples of each type Cheapest and technically simplest solution gives the best result. Mirror 10 Non-irradiated fibers Irradiated fibers (50 fb-1 eq.) With Mirror Without Mirror Relative photon yield vs distance from SiPM 11 In UX85 LHCb cavern: Cooled vs non cooled SiPM Radiation hardness studies and simulation have shown that SiPM shall be cooled down to ~-40C to operate smoothly over the entire LHCb upgrade ( MeV n eq.) Radiation hardness studies and simulation have shown that SiPM shall be cooled down to ~-40C to operate smoothly over the entire LHCb upgrade ( MeV n eq.) Dark Current Time Observation: Dark current increase with absorbed dose Possible annealing effect SiPM dark current is reduced by a factor ~2/8C SiPM arraysScintillating FibersCooling pipe Cooling SiPM to -40 C Many configuration envisaged to optimize heat transfers Heat load dominated by incoming heat transfer (SiPM power < 2w/module) Insulation thickness defined by dew point in LHCb cavern (