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LUCID – A Progress Report PowerPoint Presentation
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LUCID – A Progress Report

LUCID – A Progress Report

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LUCID – A Progress Report

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  1. LUCID – A Progress Report James Pinfold for the ATLAS Luminosity & Forward Physics Working Group James Pinfold Manchester Meeting December 2005

  2. Lucid Interest Group (8 Groups,~ 35 People) • University of Alberta (Lead group, detector, gas system, simulation, optical-fibre cables) • W. J. McDonald, J. L. Pinfold, J. Soukup (chief engineer), Y. Yao. • University of Bologna (Readout electronics, DAQ) • A. Bertin, M. Bruschi, S. De Castro, I. D’Antone, L. Fabbri, P. Faccioli, B. Giacobbe, F. Grimaldi, I. Massa, M. Piccinini, M. Poli, C. Sbarra,N. Semprini-Cesari, R. Spighi, M. Villa, A. Vitale, A. Zoccoli • CERN (simulation) • S. Ask, P. Grafstrom, • University of Lund/CERN (Forward shielding) • V. Hedberg (forward shielding) • University of Manchester (DAQ) • Some initial interest in LUCID DAQ issues • University of Montreal(Radiation hardness studies) • C. Leroy, J-P Martin. • CERN (Installation,integration, mech., gas system) • T. Hott James Pinfold Manchester Meeting December 2005

  3. Physics Aims for LUCID • LUCID, calibrated with the measurement of elastic scattering in the Coulomb region, will provide a luminosity measurement to a few percent (at worst) of the luminosity across the whole lumi-range of ATLAS. • LUCID would provide an online LUMI monitor capable of “following bunches”. • OTHER USES: • As part of a rapidity gap trigger for the diffractive physics program • It could provide an online determination of the event plane of an event in heavy-ion running James Pinfold Manchester Meeting December 2005

  4. Where is LUCID Deployed? ηMAX = -ln (tan 0.132º) = 6.073 to ηMIN= -ln (tan 0.266º) = 5.374 Front face of each LUCID end is ~17m from the IP James Pinfold Manchester Meeting December 2005

  5. The LUCID Luminosity Monitor A bundle of 200 (per end) projective Al Cerenkov tubes around the beam pipe Radiator gas C4F10 or Isobutane Light taken out to remote PMTs (or APDs) via quartz fibres James Pinfold Manchester Meeting December 2005

  6. The Optical Read-out Winston cones Cerenkov tubes Optical fibre readout James Pinfold Manchester Meeting December 2005

  7. Radiation Levels LUCID REGION James Pinfold Manchester Meeting December 2005

  8. Reading out LUCID James Pinfold Manchester Meeting December 2005

  9. The Engineering Change Report • The main issue raised was the necessity to align LUCID in the available space - this required us to reduce the outer diameter of LUCID as shown • To optimize the use of the space we: • Reduced the number of LUCID layers to 4 • Increased the number of Cerenkov tubes/layer to 42. James Pinfold Manchester Meeting December 2005

  10. LUCID Technique – Tested at CDF • Sensitive to primaries – that give more light than secondaries & soft particles: • Much shorter paths for secondaries • Cerenkov thresholds • No Landau fluctuations for Cerenkov emission…a narrow single particle peak • Excellent amplitude resolution - we can count multiple tracks/tube - No saturation even at highest luminosity • Linear relationship between lumi & tracks counted in CLC • 200 Al tubes/end give position sensitivity • Time resolution (~140ps @ CDF) –we can “follow bunches”. • Radiation hard –it can fit in available space & has low mass (~40kg/end – for 1 bar, ~60kg/end for 2bar running Linear response No Saturation James Pinfold Manchester Meeting December 2005

  11. LUCID –Dynamic Range & Calibration • LUCID can monitor luminosity over the full range expected at the LHC (1027 1034) interactions / bunch  ~ 2 x10-4 ~20 (a factor of 105) • Required dynamic range of the LUCID detector up to ~ 34 tracks (~1.7 x 20). • The detector can also be run “independently” in order to assess: 1) beam background conditions, 2) beam quality & beam position • The LUCID detector exploits the expected linear dependence between # reconstructed particles and # pp interactions (min. bias) to full lumi. CALIBRATION Calibration can be carried from elastic scattering data over the full dynamic range James Pinfold Manchester Meeting December 2005

  12. Light Output Estimates Results available from a full GEANT-4 simulation of LUCID Number of photons trapped in fibres Doubling the pressure would in principle double the number of photons James Pinfold Manchester Meeting December 2005

  13. Triggering & Monitoring - Proposals • A general beam crossing trigger employed but LUCID only be read out when a physics trigger is obtained • However monitoring tasks sum over each beam crossing (scalars) Main Goals of the LUCID electronics: • For each triggered event (ROD level): • Number of tracks • Track arrival time • Output of monitoring scalars • Tracks/tube? • Monitor level • Number of tracks per bunch • Track arrival time per bunch • Background levels • Trigger Level • Provide a fast trigger on “properly” filled bunch (multiplicity cut) or on-time events • Provide a Rapidity-Gap veto for forward physics James Pinfold Manchester Meeting December 2005

  14. Electronic Readout • Photo-detector- the 64 channel HAMAMATSU H7546B-03 (baseline) with UV glass window • But we will also investigate the use of SiPMTs/ APDs at future test-beam. • Electronics in early stages of development but main system architecture is in place • Readout structure modeled as closely as possible on Roman Pot electronics. • Main elements of the readout: • OPERA MAROC chip adapted to LUCID needs from the RP design (ATLAS Orsay group) • Gated Integrator + ADC 8 bit for the total sum- liasing with LHCb preshower group (Clermont) for adapting their GI+ADC solution • TDC: 25 ns full range- CERN HPTDC used. • LOGIC Mainly Based on LUT (still to be optimized) implemented n FPGAs • Engineering Integration has to be studied but standard VME 9U is current baseline H7546B-03 James Pinfold Manchester Meeting December 2005

  15. System Optimization-Test Beam+MC • Study the best solution for LUCID readout (gas pressure, number and type of fibres per tube, MAPMT/SiPMT/APD, etc.)  using test beam • We took test-beam data at DESY from October 24th – November 14th, with a 6-tube prototype, in collaboration with the RP group • Main goals of the test-beam from 10/10/05 - 14/11/005, to study: • Photon generation, transfer and losses • Generation, processing and transmission of electrical signals • Baseline Readout Device: MAPMT H7546 • MC Study to refine design parameter (TDC & ADC resolution), occupancy, trigger algorithm, readout and backgrounds in fibre readout and Cerenkov tubes • Next test beam dates: • Next team date at DESY - March 27 to April 10th • First CERN test beam date: June 28 – July 12 • Second CERN test beam date: October 26 – November 5 James Pinfold Manchester Meeting December 2005

  16. Testbeam in DESY The T22 teststand is equipped with a silicon microstrip telescope arranged in 3 stations with 640 x+y strips covering 32 X 32 mm2 Resolution ≈30µm (Roman Pot) (LUCID) James Pinfold Manchester Meeting December 2005

  17. Testbeam Snapshots Front window of gas vessel under pressure test (3bar) Fibre-optic calibration pulser Winston cones Fibre optic connection Rotation mount James Pinfold Manchester Meeting December 2005

  18. Test-beam – Lessons • Test-beam planned in late summer ’05 took place from 10/10/05- 14/11/05 Data taken : • High Statistics scans across the mouths of the tubes • High Statistic scans across q (the angle of the axis of the tube with beam direction) • With absolute pressure varying from 1 Bar to 2.5 Bar • With two gases: isobutane and C4F10 • Scans across fibre optic pig-tails • We are still working on the data but this initial test was successful • These upgrades will be made for the next test beam in March-April ‘06: • Reflectivity of Cerenkov tubes & Winston cones will be increased • New fibre optic readout with better UV transmission will be employed • Elements of the final readout will be employed • New fibre-optic connection scheme for the MaPMT • We are planning to test SiPMTs

  19. Conclusions • LUCID can rely on quite settled technologies both on the detector and the electronics side  we are planning to take data with LUCID in 2007 • The activities around the detector and the electronics are ramping up  test beam studies started in Oct/Nov 2005 at DESY on a 6-tube prototype at DESY (in the co-operation with the RP group) • The test-beam program will continue: • Next team date at DESY - March 27 to April 10th • First CERN test beam date: June 28 – July 12 • Second CERN test beam date: October 26 – November 5 • The test beam results+MC simulation will allow to finalize the detector +electronic design in several months from now • The details of the integration of the system in the ATLAS Trigger+DAQ scheme has started James Pinfold Manchester Meeting December 2005

  20. The ATLAS Detector Tracking: Calorimetry: James Pinfold Manchester Meeting December 2005

  21. Numerical Aperture • The arc sine of the numerical aperture is the critical angle • The acceptance angle of the fibre is twice the critical angle • Thus a fibre of NA 0.37 has acceptance angle = 43.4o