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Recirculation Concept - Cyclotron PowerPoint Presentation
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Recirculation Concept - Cyclotron

Recirculation Concept - Cyclotron

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Recirculation Concept - Cyclotron

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  1. Recirculation Concept - Cyclotron Radio frequency alternating voltage D-shaped RF cavities time t =0 Lawrence: 4” – 80 keV 11” - 1.2 MeV Hollow metal drift tubes time t =½ RF period • Orbit radius increases with momentum • Orbital Frequency independent of momentum • Particle motion and RF in phase

  2. Equilibrium Orbit Magnetic Force Centrifugal Force = Constant revolution frequency momentum radius magnetic field

  3. Synchrotron Ring Schematic Bending magnets Accelerating Voltage • During acceleration, momentum increases • Increase magnetic field during acceleration. • Constant orbital radius Vacuum tube Focusing magnets

  4. Colliding Beam Synchrotron

  5. Equilibrium Orbit momentum Constant revolution frequency radius magnetic field

  6. CERN Seen from the Air • Tunnels of CERN accelerator complex superimposed on a map of Geneva. • Accelerator is 50 m underground • 25 km in circumference

  7. Alors, c’est fini! Et maintenant?

  8. Interaction of Charged Particles with Matter All particle detectors ultimately use interaction of electric charge with matter Track Chambers Calorimeters Even Neutral particle detectors Ionization Multiple Scattering Cerenkov Transition Radiation Electron’s small mass - radiation

  9. How we did it in the past – Bubble Chamber Magnet

  10. You could actually see what was going on 1960s computer

  11. Bubble Chamber – ionization trails in superheated liquid hydrogen Electron knocked out of atom Spirals in magnetic field

  12. Generic Detector • Layers of Detector Systems around Collision Point R.S. Orr 2009 TRIUMF Summer Institute

  13. Generic Detector • Different Particles detected by different techniques. • Tracks of Ionization – Tracking Detectors • Showers of Secondary particles – Calorimeters R.S. Orr 2009 TRIUMF Summer Institute

  14. Generic Detector • Different Particles detected by different techniques. • Tracks of Ionization – Tracking Detectors • Showers of Secondary particles – Calorimeters R.S. Orr 2009 TRIUMF Summer Institute

  15. Computer Display of Event • Layers of Detector Systems around Collision Point R.S. Orr 2009 TRIUMF Summer Institute

  16. ATLAS Detector • Different Particles detected by different techniques. • Tracks of Ionization – Tracking Detectors • Showers of Secondary particles – Calorimeters R.S. Orr 2009 TRIUMF Summer Institute

  17. ATLAS Wedge • Different Particles detected by different techniques. • Tracks of Ionization – Tracking Detectors • Showers of Secondary particles – Calorimeters R.S. Orr 2009 TRIUMF Summer Institute

  18. Wire Chamber R.S. Orr 2009 TRIUMF Summer Institute

  19. 3 stages in signal generation 1) Ionization by track passing through cell 2) Ionization drifts in E field time • 3) In high E field region near wire, primary ionization electrons gain enough energy to start ionizing the gas • Avalanche • More charges • Charge amplification • Noise free amplifier microvolt signal if no amplification R.S. Orr 2009 TRIUMF Summer Institute

  20. Generic Detector R.S. Orr 2009 TRIUMF Summer Institute

  21. Generic Detector R.S. Orr 2009 TRIUMF Summer Institute

  22. Simple Drift Chamber R.S. Orr 2009 TRIUMF Summer Institute

  23. TRT endcap A+B TRT barrel Pixels TRT endcap C SCT endcap SCT barrel The ATLAS Inner Detector

  24. ATLAS Tracker R.S. Orr 2009 TRIUMF Summer Institute

  25. Inner Detector (ID) • The Inner Detector (ID) comprises four sub-systems: • Pixels (0.8 108 channels) • Silicon Tracker (SCT) • (6 106 channels) • Transition Radiation Tracker (TRT) • (4 105 channels

  26. ATLAS Wedge • Different Particles detected by different techniques. • Tracks of Ionization – Tracking Detectors • Showers of Secondary particles – Calorimeters R.S. Orr 2009 TRIUMF Summer Institute

  27. PN Junction R.S. Orr 2009 TRIUMF Summer Institute

  28. SCT barrel

  29. Pixel Layer-2 – half shell Pixel Layer2, once clamped, outside “Ready for installation” date is 1st April 2007 Pixel Layer2, once clamped, inside

  30. ATLAS Wedge • Different Particles detected by different techniques. • Tracks of Ionization – Tracking Detectors • Showers of Secondary particles – Calorimeters R.S. Orr 2009 TRIUMF Summer Institute

  31. Why Is It Called a Calorimeter? Charged Particle Electrical Signal Proportional to Incoming Energy Liquid Argon/Metal Kinetic Energy of Particle Converted to Ionization Of Liquid Argon Readout Electronics

  32. Comparison of Hadronic & Electromagnetic Showers R.S. Orr 2009 TRIUMF Summer Institute

  33. LAr and Tile Calorimeters Tile barrel Tile extended barrel LAr hadronic end-cap (HEC) LAr EM end-cap (EMEC) LAr EM barrel LAr forward calorimeter (FCAL)