1. QUARTIC- A Precise ToF Detector for the FP420 Project James Pinfold For the QUARTIC Working Group René Magritte: Empire of Light

2. The QUARTIC Working Group University of Alberta: Lars Holm, James Pinfold, Drew Price, Jan Schaapman, Yushu YaoUniversity of Alberta: Lars Holm, James Pinfold, Drew Price, Jan Schaapman, Yushu Yao Fermilab: Mike AlbrowFermilab: Mike Albrow University of Texas at Arlington: Andrew Brandt, Chance Harenza, Joaquin Noyola, Pedro DuarteUniversity of Texas at Arlington: Andrew Brandt, Chance Harenza, Joaquin Noyola, Pedro Duarte Associated Group University of Louvain: Krzysztof PiotrzkowskiUniversity of Louvain: Krzysztof Piotrzkowski James Pinfold Manchester Meeting December 2005

3. Initial Conception of Quartic AIM: Use a precise ToF Cerenkov detector to match z(vertex) with central track vertex and thus reduce backgrounds to, for example, exclusive diffractive Higgs productionAIM: Use a precise ToF Cerenkov detector to match z(vertex) with central track vertex and thus reduce backgrounds to, for example, exclusive diffractive Higgs production Z of interaction = c(TR-TL)/2 where TR(TL) is the time measured in the RHS(LHS) QUARTIC detectors (420m from IP) -Z of interaction = c(TR-TL)/2 where TR(TL) is the time measured in the RHS(LHS) QUARTIC detectors (420m from IP) - We have  z (mm) =0.21  t (psec) (2.1 mm for  t=10 ps [c  t/ √ 2]) TL TR TL TR z_ vtx z t X We are aiming for ~10ps resolution (3mm at the speed of light) James Pinfold Manchester Meeting December 2005

4. Where do the Protons Go? y 120 GeV Higgs x 3mm SDBackground X- cmsX- m 120 GeV Higgs 3mm (420m+420m)ALL James Pinfold Manchester Meeting December 2005

5. Initial Geometry for QUARTIC* MCP-PMT proton Cerenkov Photons James Pinfold Manchester Meeting December 2005 20 fused silica bars 6mm 2 x 100 mm NB fused silica is rad-hard NB fused silica is rad-hard * From Mike Albrow

6. Achieved – a 10ps Timing Resolution Achieved – a 10ps Timing Resolution The problem is we cannot put a PMT in a 7 TeV beam. James Pinfold Manchester Meeting December 2005

7. What is a MCP-PMT? Burle 2” MCP-PMT The MCP-PMT is a micro channel plate equipped with a photocathode & (usually) a multi-anode readout James Pinfold Manchester Meeting December 2005

8. Geant4 Simulation The detector simulation includes:The detector simulation includes: –Tracking and timing of Cerenkov photons to the MCP-PMT –Wavelength dependent refractive index, attenuation & reflectivity –Ability to study cladding (eg air) or a reflective layer (with a possibility of including diffuse reflection) –The effects of coupling grease (if necessary) Al reflection (Cladding with NA=0.37) James Pinfold Manchester Meeting December 2005

9. Simulating the MCP-PMT Arrival time at the face of the MCP-PMT recordedArrival time at the face of the MCP-PMT recorded Simulate geometrical acceptanceSimulate geometrical acceptance Implement wavelength dependence of the photo-cathode QE.Implement wavelength dependence of the photo-cathode QE. Simulate PMT transit-time jitter by adding a normally distributed random time jitter with the appropriate standard deviationSimulate PMT transit-time jitter by adding a normally distributed random time jitter with the appropriate standard deviation Simulate the layout of the anode pad readout of the MCP-PMT.Simulate the layout of the anode pad readout of the MCP-PMT. Assume that when the MCP-PMT o/p voltage reaches a certain level it triggers the discriminator – this level corresponds to a certain number of photons having arrived.Assume that when the MCP-PMT o/p voltage reaches a certain level it triggers the discriminator – this level corresponds to a certain number of photons having arrived. James Pinfold Manchester Meeting December 2005

10. Cerenkov Light in Fused Silica* *UTA simulation λ#PHQE#PH*Q EΘcn 180-2501652.615.70%259.549.61.544 250-3501148.718.00%206.847.81.490 350-450624.719.90%124.347.21.471 450-550394.311%43.446.91.464 550-650271.11.50%4.146.71.458 total 4100638.0 UV is important! 640 total pe’s : ~130 pe’s/6mm rod (collection efficiency reduces this number to ~80 pe’s/bar) James Pinfold Manchester Meeting December 2005

11. Photon Arrival Times (1) red = totally internally reflected light green = extra light if aluminized Picoseconds Picoseconds QE not included First 10ps 22 photons First 20ps 51 photons First 30ps 80 photons First 40 ps 107 photons Half maximum rise time ~3ps Number of photons James Pinfold Manchester Meeting December 2005 (From Ray Tracing)

12. Photon Arrival Times (2) red = totally internally reflected light green = extra light if aluminized QE included First 10ps 3 pe’s First 20ps 8 pe’s First 30ps 12 pe’s First 40ps 16 pe’s Half maximum rise time ~3ps Picoseconds Picoseconds Number of photoelectrons James Pinfold Manchester Meeting December 2005 (From Ray Tracing)

13. QUARTIC Background Rejection (1) A.2 single diffractive protons overlapping a hard scatter B.A hard scatter with an overlapping double pomeron event C.A hard single diffractive event overlapping a soft diffractive event Rule of thumb: ~1% of interactions have a proton at 420m 97.4% of events have primary (PV) vertex and fake vertex (FV) more than 2.1mm (1  ) apart. PV FV 97.8% of events have primary (PV) vertex and second vertex (SV) more than 2.1mm (1  ) apart. 95.5% of events have primary (PV) vertex and fake vertex (FV) more than 2.1mm (1  ) apart. PV SV FV James Pinfold Manchester Meeting December 2005

14. Background Rejection (2) A.Two single diffractive protons overlapping a hard scatter B.A hard scatter with an overlapping double pomeron event C.A hard single diffractive event overlapping a soft diffractive event Background rejection James Pinfold Manchester Meeting December 2005

15. Frontend Readout (1 st version) Frontend Readout (1 st version) High precision Alberta CFD Aiming for 20-ps resolution.High precision Alberta CFD Aiming for 20-ps resolution. Using CERN HPTDC as key component.Using CERN HPTDC as key component. –Dead time free. –32 channels/chip 。 Size ～ 2.7×2.7 cm 2 。 –External clock ： 40MHz 。 Synchronized to bunches. Time resolution (RMS) ：Time resolution (RMS) ： –70ps medium resolution mode –35ps high resolution mode –15ps very high resolution mode (8ch per chip) 。 Double pulse resolution ： 5ns (typical); 10ns (guaranteed). Separate leading or trailing edge measurement;Double pulse resolution ： 5ns (typical); 10ns (guaranteed). Separate leading or trailing edge measurement; Simultaneous measurement of leading edge and pulse width (not true for very high resolution mode).Simultaneous measurement of leading edge and pulse width (not true for very high resolution mode). James Pinfold Manchester Meeting December 2005

16. Test-beam at Fermilab Planned for summer of 2006 (beam starts in mid-June)Planned for summer of 2006 (beam starts in mid-June) Test-beam manned by UTA and AlbertaTest-beam manned by UTA and Alberta Online/DAQ development required for QUARTIC prototype readout.Online/DAQ development required for QUARTIC prototype readout. Optical pulser & scope (TDS6804) will be used to validate electronics prior to test-beamOptical pulser & scope (TDS6804) will be used to validate electronics prior to test-beam Constant Fraction Discriminator+ HPTDC will be used to readout the detectorConstant Fraction Discriminator+ HPTDC will be used to readout the detector Full sized prototype of detector available – but not all channels readoutFull sized prototype of detector available – but not all channels readout James Pinfold Manchester Meeting December 2005

17. Design (Joint responsibility):Design (Joint responsibility): Conceptual: geometry - bars, plates, block, fibers, other?)Conceptual: geometry - bars, plates, block, fibers, other?) OptimizationOptimization EngineeringEngineering Simulation (Alberta + UTA):Simulation (Alberta + UTA): full GEANT- 4 (Alberta), ray tracing (UTA)full GEANT- 4 (Alberta), ray tracing (UTA) Radiator (UTA + Fermilab):Radiator (UTA + Fermilab): Fused silicaFused silica Surface treatment: aluminization, cladding,...Surface treatment: aluminization, cladding,... Photodetector (UTA + Alberta)Photodetector (UTA + Alberta) MCP-PMT: Hamamatsu, Burle, other? (Baseline solution)MCP-PMT: Hamamatsu, Burle, other? (Baseline solution) SiPMT, Avalanche photodiode (APD)?, other ?SiPMT, Avalanche photodiode (APD)?, other ? Mechanics, Assembly and mounting (UTA, Alberta):Mechanics, Assembly and mounting (UTA, Alberta): Engineering and manufacture (including motion control)Engineering and manufacture (including motion control) Electronics (Alberta + UTA)Electronics (Alberta + UTA) Front end Read-outFront end Read-out HV and slow controlsHV and slow controlsResponsibilities James Pinfold Manchester Meeting December 2005

18. Funding Initiatives UTA (with UofA listed as a collaborator): Texas ARP $100K/2 years, TOF and Mechanics; passed University pre-proposal stage (12/79); proposal due Feb. 14, award May 15 DOE ADR $130k/2 years, TOF only, proposal due Dec. 15! Award date June. Burle is contributing MCP-PMT’s 25  m pore (60 psec TTS), 10  m pore (~30 psec expected), 10um, dropped face plate (removes tail from recoil electrons), and high current capability version Alberta A small amount of initial funding is available(~$10K). In kind contribution from small electronics and machining costs (at 5CHF/hr!) James Pinfold Manchester Meeting December 2005

19. Conclusion The QUARTIC precision ToF detector offers the possibility of reducing physics backgrounds to exclusive central Higgs production at ATLASThe QUARTIC precision ToF detector offers the possibility of reducing physics backgrounds to exclusive central Higgs production at ATLAS ToF detector resolutions of ~10ps have been achieved previously and initial simulation studies indicate that we should be able to deploy a detector with resolution of better than 30ps at the LHCToF detector resolutions of ~10ps have been achieved previously and initial simulation studies indicate that we should be able to deploy a detector with resolution of better than 30ps at the LHC This resolution will allow us to reduce the background from events contributing central “activity” and two protons at 420m (hard scatters + diffractive & double pomeron events) by more than 90%.This resolution will allow us to reduce the background from events contributing central “activity” and two protons at 420m (hard scatters + diffractive & double pomeron events) by more than 90%. The R&D effort to develop QUARTIC is well underway with the first beam-test to take place in the summer of 2006.The R&D effort to develop QUARTIC is well underway with the first beam-test to take place in the summer of 2006. James Pinfold Manchester Meeting December 2005

20. n=1n>>1 Cerenkov Effect Use this property of prompt radiation to develop a fast timing counter particle James Pinfold Manchester Meeting December 2005

21. Readout Electronics (1 st take) James Pinfold Manchester Meeting December 2005