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Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC

Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC. University of Siena I.N.F.N. Pisa Department of Physics TOTEM -T2 TRIPLE GEM DESCRIPTION OF SIENA ACTIVITY E. Oliveri. Outline.

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Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC

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  1. Total Cross Section, Elastic Scattering and Diffraction Dissociation at the LHC University of Siena I.N.F.N. Pisa Department of Physics TOTEM -T2 TRIPLE GEM DESCRIPTION OF SIENA ACTIVITY E. Oliveri Totem Collaboration Meeting 8 June 2006

  2. Outline • PART I TRIPLE GEM CHAMBER Assembly • PART II Siena TRIPLE GEM Testing Laboratory • PART III TRIPLE GEM Simulation • PART IV Time Schedule Totem Collaboration Meeting 8 June 2006

  3. Outline Part I • CERN • Components • G&A Engineering • Assembly & preliminary test • Siena Physics Department – I.N.F.N. Pisa • Protocol and equipment for the assembly • of the chamber • Test of the chamber • Simulation & data analysis TRIPLE GEM CHAMBER Assembly • Partners • Assembly and Test at G&A Engineering • Problems and upgrading of assembly process Totem Collaboration Meeting 8 June 2006

  4. Assembly and preliminary test at G&A Engineering Pressure Test: Dp<1mbar @ 11.5mbar OVP in 15’ Leakage Current Test: I<100pA for 5’ @ 500V for every foil Totem Collaboration Meeting 8 June 2006

  5. Problems and upgrading of assembly process Problems • Gas line interrupted between the chamber and the gas fitting. • Glue on electrodes foil Upgrading • A more accurate inspection of incoming components. • Automatic deposition with undervacum degassed glue (already used). • Cut foils borders before the final assembly. • Stretch the DRIFT foil (using the plexiglass chassis) before sticking it on the spacer. Totem Collaboration Meeting 8 June 2006

  6. Outline Part II Siena TRIPLE GEM Testing Laboratory • Gas Supply System • TRIPLE GEM Support & Services • Power & Acquisition Systems Totem Collaboration Meeting 8 June 2006

  7. PRESSURE CONTROL: • Pressure on the chamber in the range of mbar, avoiding overpressure bigger than 10mbar • FLOW CONTROL: • Control of fluxes of nearly 2-6 l/h of Ar-CO2 (70-30) Gas Supply System The Requirements Totem Collaboration Meeting 8 June 2006

  8. First Stage Pressure Reduction P3=0.5-8 bar AirLiquide HBS 240 8 3 (Double Stage) Flow Control ROTAMETER VOEGTLIN V300 (3l/h-5l/h-16l/h) + Q-Flow valve NS2 Secon Stage Pressure Reduction P5=5-50 mbar TESCOM-EUROPE Regulus1 - 5-50mbar (Single Stage) G1 G2 V1 V2 V3 TP1 TP3 G3 RM P1=100 bar V4 V6 BB1 V8 V5 V7 V9 V10 BB2 TP4 TP2 F1 NUPRO filter SS-2TF-LE 0.5 mm Gas Supply System The Project Special Thanks to A.Morelli, I.N.F.N Genova, for suggestions & components. Totem Collaboration Meeting 8 June 2006

  9. The Gas Supply System Term of delivery for the pressure reducer postponed to half june for manifacturing problems Variable Area Flowmeter mbar Differential Pressure Gauge Totem Collaboration Meeting 8 June 2006

  10. Strips and Pads ReadOut TRIPLE GEM Support & Services Strips & Pads Connections GND Connection Gas Supply HV Supply Totem Collaboration Meeting 8 June 2006

  11. TRIPLE GEM Support & Services Mechanical Workshop The mechanical workshop: C. Stanghini & L. Stiaccini. Totem Collaboration Meeting 8 June 2006

  12. 4CH LeCroy 1GHz Oscilloscope Leakage Current Measurement Keithley 6485 Picoammeter Power & Acquisition System High Voltage Power Supply Strips & Pads Signal Measurement 4CH Digital Oscilloscope TDS 3034B Tektronix 300MHz 2.5GS/s ADC - 2249W LeCroy 12 Channels 4 CH High Voltage Power Supply CAEN N472 High Voltage Power Supply Monitoring Strips Read Out Board 16 Groups, each of 8 strips Pads Read Out Board 15 Groups, each of 8 pads Keithley 2700 Multimeter + Scanner Totem Collaboration Meeting 8 June 2006

  13. Power & Acquisition System Electronical Workshop The electronical workshop: R. Cecchi Developmement of readout board for single strip & single pad signal acquisition Totem Collaboration Meeting 8 June 2006

  14. Power & Acquisition System Acquisition System Delay lines ADC Modules Dual Timer CAEN Multiscaler 8Ch. 100MHz 8Ch. Low THR Discriminator CAEN Cosmic-Ray acquisition system Coincidence Unit LeCroy ~2cm x 2cm Totem Collaboration Meeting 8 June 2006

  15. Outline Part III TRIPLE GEM Simulation • Software Tools • Maxwell2dSV • The Garfield approach • Signal analysis: • time, space & intensity • strip & pad signals Totem Collaboration Meeting 8 June 2006

  16. TRIPLE GEM Simulation Software tools Special Thanks to D.Pinci, LHCb Roma-Cagliari Group, for precious initial input. Garfield: Main framework. Maxwell2DSV: Electric field map. Magboltz: Electron/ion drift velocity and diffusion coefficients. Imonte:Townsend and attachment coefficients for given gas mix. Heed: Energy loss by ionization in gas; cluster production. Totem Collaboration Meeting 8 June 2006

  17. The hole field Map The weigthing Field (Ramo Th.) TRIPLE GEM Simulation The Field Maps - Maxwell2DSV 3D Analysis from Maxwell2DSV obtained by symmetry operation Others Electrodes & Conductors @ GND Readout Electrode @ 1V 3D Analysis from Maxwell2DSV obtained by symmetry operation 2D Software limitation: We can’t simulate more than one hole 3D Software upgrape: The elementary cell allow simulations that involve near holes 2D Software limitation: In pad signal analysis we can’t have a simulation close to four pads corner 3D Software upgrape: We can describe all elctrodes configuration Totem Collaboration Meeting 8 June 2006

  18. DRIFT GEM foil TRANSFER GEM foil TRANSFER GEM foil INDUCTION The Drift Zone The Transfer Zone TRIPLE GEM Simulation The Garfield approach -Ionization process -Diffusion and drift toward the Gem t & st transfer y n t & st drift Diffusion and drift between the Gem planes sxz transfer sxz drift The Induction Zone The GEM foil Avalanche in the Gem planes t & st induction sxz induction -Diffusion and drift toward the electrodes -Signal induction Gain Totem Collaboration Meeting 8 June 2006 I(t)

  19. m 10Gev in Ar-CO2 (70-30) @ stp Mean ~ 27 Most Probable Value ~ 13 RMS ~ 30 TRIPLE GEM Simulation Drift Zone heed 0.3 cm 94 x 0.3 ~ 28 Totem Collaboration Meeting 8 June 2006

  20. 5kV/cm in 2mm 5kV/cm in 2mm DRIFT VELOCITY TRIPLE GEM Simulation The Transfer Zone magboltz ~8 cm/ms @5kV/cm mean ~ 26ns t = d/v = (0.2 / 8) ms= = 2.5 e-2 ms = 25 ns Ar-CO2 (70-30) DIFFUSION COEFFICIENTS magboltz ~260 um for 1 cm @5kV/cm rms~115mm Ar-CO2 (70-30) Totem Collaboration Meeting 8 June 2006

  21. TRIPLE GEM Simulation The multiplication process Mean G ~ 15 No outgoing e- ~30% Townsend Coeff. Totem Collaboration Meeting 8 June 2006

  22. Signal on PAD EFFECTS OF ELECTRODES CONFIGURATION ON DIRECT & CROSS CURRENTS The weigthing Field TRIPLE GEM Simulation Signal Collection Direct Electrodes Configuration: ONLY PADS ~ 370 nA Cross 0 nA Ramo Theorem Ik(t) = -qv(x,t)xEkw(x) Electrodes Configuration: PADS & STRIPS Direct ~ 150 nA Cross Totem Collaboration Meeting 8 June 2006 ~ 70 nA

  23. TRIPLE GEM Simulation Starting Point for signal collection Lateral position and arrival time for 1k e- uniformly distributed in drift zone From 1k e- uniformly distributed in drift zone, diffusing for 7 mm in a field of 3 kV/cm in Ar/CO2 (70/30) @ STP X end DRIFT GEM1 GEM2 GEM3 READOUT t end Neglecting GEM planes holes effects -Readout current results normalized to 1k primary electrons -Expected current obtained multiplying by <Ne> in drift zone (27) and by total gain (G3-GEM ~ 3.4x103) Totem Collaboration Meeting 8 June 2006

  24. TRIPLE GEM Simulation Signal Time analysis DRIFT h e- td h e- GEM1 Signal of electrons not collected by the readout electrode td t CROSS SIGNAL GEM2 GEM3 ti READOUT Signal of electrons collected by the readout electrode Readout Pad DIRECT SIGNAL DRIFT VELOCITY ~7000 cm/usec @3kV/cm td t td ti Ar-CO2 (70-30) Totem Collaboration Meeting 8 June 2006

  25. DRIFT DRIFT GEM1 GEM1 GEM2 GEM2 GEM3 GEM3 Readout Pad Readout Pad Neglecting GEM planes holes effects TRIPLE GEM Simulation Signal Space analysis sx~300 mm 10mm Upgrading to consider the effects of GEM planes holes READOUT DIFFUSION COEFFICIENTS ~260 um for 1 cm @3kV/cm Trasversal Longitudinal x1 x6 x6 Ar-CO2 (70-30) x6 x6 x12 x6 x12 x6 Totem Collaboration Meeting 8 June 2006

  26. TRIPLE GEM Simulation Signal Intensity & Shape MULTIPLICATION FACTORS Number of el. produced per incident particle ELECTRONS COLLECTION Number of el. collected by electrode as direct induced current (e- captured by the readout electrode) or cross induced currents (e- captured by the others electrodes) Gas & Drift Zone Length ReadOut Geometry & Spatial distribution of the electrons cloud Mean ~ 27 Most Probable Value ~ 13 RMS ~ 30 DRIFT <Ne> G1 GEM1 G2 GEM2 GEM3 G3 READOUT Weigthing field lines Readout Pad Mean G ~ 15 TripleGem Voltage, Gas & GEM foil geometry ReadOut Geometry Totem Collaboration Meeting 8 June 2006

  27. TRIPLE GEM Simulation Strips Signals Totem Collaboration Meeting 8 June 2006

  28. TRIPLE GEM Simulation Pads Signals Totem Collaboration Meeting 8 June 2006

  29. Outline Part IV Time Schedule Totem Collaboration Meeting 8 June 2006

  30. Time Schedule The lab is available 16 30 Work on simulation (from 100% to 0% of working time) Planning and manufacturing of the test board Cosmic Ray Signal Apparatus test (coincidence and scintillators’ signal on oscilloscope) Pinci’s Meeting Simulation Software 17 28 HV and 2 simple readout Board in Siena The G&A Triple GEM in Siena Gas System Assembly & test Second Stage Pressure Reducer Order 17 23 24 26 4 Ar-CO2 Cylinder in Siena 15 First Stage Pressure Reducer in Siena Morelli in Siena Gas System Planning & Companies Contacts First Contact With Morelli Term of delivery for the pressure reducer Manifacturing problems New term of delivery half june Totem Collaboration Meeting 8 June 2006

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