The Inner Tracker detector of the LHCb experiment.

Transcription

1 The Inner Tracker detector of the LHCb exeriment. CERN and LHC LHCb detector Inner Tracker EPFL

2 CERN and LHC Large Hadron Collider * collisions * 7 TeV er beam 4 exeriments: CMS & Atlas Alice and LHCb m * 27 km circumference * oerational: km

3 Inner Tracker Trigger Tracker Diole Magnet Outer Tracker Vertex Locator Calorimeters rad m 0 25 Muon chambers 10 mrad 3 RICH Overview: Inner Tracker Design Challenges Production LHCb Tracking LHCb detector is designed to erform recise measurement of CP violation using B decays and to robe new hysics. > see talks S. Jimenez Otero, F. Legger, J. Borel

4 Vertex Locator rad m mrad 4

5 Vertex Locator rad m mrad 5 Ring Imaging Cherenkov Counter

6 Trigger Tracker Vertex Locator 2 50 m rad 10 mrad 6 Ring Imaging Cherenkov Counter

7 Trigger Tracker Diole Magnet Vertex Locator 2 50 m rad 10 mrad 7 Ring Imaging Cherenkov Counter

8 Trigger Tracker Diole Magnet Vertex Locator Outer Tracker rad m mrad Inner Tracker 8 Ring Imaging Cherenkov Counter

9 Trigger Tracker Inner Tracker Diole Magnet Outer Tracker Vertex Locator ra 2 50 m d 10 mrad 9 Ring Imaging Cherenkov Counter

10 Trigger Tracker Preshower and Inner Tracker Diole Magnet Outer Tracker calorimeters Vertex Locator rad m mrad 10 Ring Imaging Cherenkov Counter

11 Inner Tracker Trigger Tracker Diole Magnet Outer Tracker Vertex Locator Preshower and calorimeters 250 m rad Muon chambers 10 mrad 11 Ring Imaging Cherenkov Counter

12 Where is the Inner Tracker? Inner Tracker consists of of 3 stations, surrounded by the Outer Tracker The Inner Tracker 2 boxes with 2 Si sensors modules 2 boxes with 1 Si sensor modules The comlete IT detector is located inside the accetance (hybrids, cb s, cooling, cabling, ) 1,3 % of satial accetance, 20% of tracks. 12

13 Si sensor Pitch Adator + hybrid with Beetles. Katon insulation Aluminium Mini Balcony Airex Carbon Fiber suort foam layer: cools the sensors Ladders are attached via the mini balcony on a cooling rod, through which runs a cooling liquid detector is cooled (5 C) to avoid thermal runaway and to reduce radiation damage to remove heat from the front end electronics Readout Cables, High and Low voltage cables Cooling System 13

14 Challenges of the Silicon Tracker. 1. Large areas have to be covered in Silicon. Long readout stris More load caacitance (17 f) which increases the noise Chi front end design Adated sensor thickness Large distance between readout stris (since moderate requirements on resolution) Decreases S/N in between stris otimise width/itch of the stris left stri right stri 2. Bunch crossings every 25ns fast shaing time Increases noise Otimised front end electronics 3. Momentum resolution is limited by multile scattering minimization of material for the accetance: Thin sensors Thinner sensors reduces S/N Best comromise

15 Production Organisation 4 Universities EPFL: Module roduction + testing (Lausanne) Bonding (Cern) Universidad de Santiago: Detector box Bonding M.I.P Heidelberg: Readout chi design Hybrid testing University of Zurich: Sensor testing

16 Production Status Inner Tracker: 3 stations with 336 (+15% sare) modules in total are to be roduced and tested Production Strategy: Parallel roduction of modules using several jigs Testing: * Metrology * Electrical test to find broken or unbonded stri * Accelerated aging tests with heat cycles * Visual checks Scheduel: Prototying finished in August 2005 Right now in full roduction status Installation in the LHCb it in Setember 2006

17 Silicon roject: essential art for the tracking of the LHCb detector Reconstruction is not a trivial task LHCb reconstructs about 50 rimary articles er event: 30% radiation length between interaction oint and Rich2 Secondary articles Multile scattering Degrades the momentum resolution Different strategies according to the track tye Interaction every 25 ns Sillover from revious bunch crossings Search for seeds + match or extraolate with measurements in other stations 2 criteria

18 Tracking Performance on long tracks Momentum deendent: B articles have higher momentum Monte Carlo simulation (Geant 4, Pythia) Track finding efficiency ~95% Cut out in hysics analysis

19 Conclusion A tracking strategy has been imlemented and studied in detail. The simulation shows a satisfactory erformance. The roduction of the LHCb's Inner Tracker detector is well underway and installation is foreseen in Setember The Lausanne Inner Tracker Team