LHCb, Collaboration

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The LHCb Inner TrackerLHCb: is a single-arm forward spectrometer dedicated to B-physics acceptance:  15-300(250)mrad:The Outer Tracker:covers the large surface area with straw tube detectorsThe Inner Tracker:silicon strip detectors•1.3% of the acceptance •20% of the tracksThe ChallengesUnlike vertex detectors we have:• moderate spatial resolution requirement   (~60µm)• moderate radiation environment. After 10 years: 1 Mrad or 9·1012cm-2 of 1 MeV Neutron equiv. in IT But we need to cover a large detector area:• minimize: R/O channels ⇒ large pitch O(200µm)(limits charge collection)⇒ long strips 22cm (?noise)• 40MHz, fast readout  ⇒ (?noise)• minimize material        ⇒ “thin” sensors(limits amount of  charge)p-n silicon micro-strip Hamamatsu sensors384 AC coupledreadout strips108 mm long strips,197µm pitch, w/p=0.25320(410)µm thicknesscooling “balcony” for mounting and positioning  of the ladder on the supporting cooling rod which is connected to the liquid cooling systemreadout hybrid with 3 Beetle chips in 0.25µm CMOS technology operating at 40MHz. The 128 channel front-end signals are pipelined for 160 bunch crossings. The output data are multiplexed on 4 readout ports allowing for a readout in 900ns after a trigger.Carbon Fibre (CF) support produced out of high thermal conductive fibre used to cool the sensors and the detector boxcovers the high Inner TrackerLHCbThe particle density region near the beam pipe and the bending plane of the magnet in the tracking stations behind the magnet withSilicon Strip detectors. The total area of Silicon is ~4.3m2The Inner Tracker Silicon ModuleThe Inner and Outer Tracker SupportThe Inner and Outer Trackers have individual rail systems on a common support structure. This allows individual access to both sub-detectors and their electronics  Inner Tracker boxOuter TrackerCF support barsrail systemService boxes where the analog signals from the readout chip are digitised and then optically transmitted to the counting house where they are further processed ? TELL1Production of Inner Tracker Modules•operation at ~5°C •liquid C6F14 cooling system for cooling readout hybrid and sensors•thermally conductive CF support•box enclosure lightweight isolation foam + Al foil for electrical shielding•the analog signals from the readout hybrids are sent via 5m copper cables to the service boxes outside of the acceptance where they are digitisedThe Inner Tracker LayoutThe Inner Tracker consists of•4 individual boxes per station•4 layers per station: (2 stereo layers)?336 modules: 11 and 22cm long129k readout channels on 4.3m2 siliconsensors are positioned according to their edges on a special jig, picked up by a vacuum tool and placed on the CF-support, where glue is applied using a glue dispenserthe readout hybrid is glued together with the pitch-adapter to the CF-supportbonding machine used to make the electrical connection between readout hybrid,pitch-adapter and sensors •Sensors•Kapton•Carbon Fibre•AIREX faom•Carbon Fibre

LHCb: Inner Tracker

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