1. Antonio Zoccoli RICH 2007 – Trieste 1 October 20, 2007 LUCID* - A Cherenkov tubes based detector for monitoring the ATLAS luminosity LUCID* - A Cherenkov tubes based detector for monitoring the ATLAS luminosity Antonio Zoccoli – University & INFN - Bologna For the LUCID collaboration (Alberta, Bologna, CERN, LUND) Antonio Zoccoli – University & INFN - Bologna For the LUCID collaboration (Alberta, Bologna, CERN, LUND)

2. Antonio Zoccoli RICH 2007 – Trieste 2 October 20, 2007 Detectors requirements Detectors requirements Test beam results & Rad. Hard. Measurements Test beam results & Rad. Hard. Measurements Detector design and installation strategy Detector design and installation strategy Present status of the detector Present status of the detector Conclusions Conclusions Outline Outline Outline Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID Design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

3. Antonio Zoccoli RICH 2007 – Trieste 3 October 20, 2007 Forward detectors in Atlas Forward detectors in Atlas

4. Antonio Zoccoli RICH 2007 – Trieste 4 October 20, 2007 LUCID is an array of Cerenkov tubes (length ~1.5m) made of polished aluminium using C4F10 gas as a radiator LUCID is an array of Cerenkov tubes (length ~1.5m) made of polished aluminium using C4F10 gas as a radiator The Cerenkov threshold (10 MeV for e’s 2.8 GeV for  ’s) + the pointing of the tube to the IP suppresses background from non-pointing soft secondaries and scatters The Cerenkov threshold (10 MeV for e’s 2.8 GeV for  ’s) + the pointing of the tube to the IP suppresses background from non-pointing soft secondaries and scatters It is possible to count multiple particles traversing the length of the same tube (no Landau Fluctuations) It is possible to count multiple particles traversing the length of the same tube (no Landau Fluctuations) A good time resolution ( ~2ns) allows individual beam crossings to be studied A good time resolution ( ~2ns) allows individual beam crossings to be studied This technique was first used at CDF (the CLC) This technique was first used at CDF (the CLC) LUCID – The Basic Concept LUCID – The Basic Concept The Cerenkov light is produced at ~3 o making ~ 3 reflections as it passes down the length of the tube Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID readout LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

5. Antonio Zoccoli RICH 2007 – Trieste 5 October 20, 2007 Front face of each end LUCID is ~17m from the IP PHASE 1  6.0 > |η| > 5.6 The Location of LUCID The Location of LUCID Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

6. Antonio Zoccoli RICH 2007 – Trieste 6 October 20, 2007 LUCID has to count the number of particles hitting the detector that are consistent with originating from the IP LUCID has to count the number of particles hitting the detector that are consistent with originating from the IP  There is a linear relationship between the number of particles detected and the luminosity The detector has to cope to high radiation levels  All parts (especially PMTs) must be rad. hard. The detector has to cope to high radiation levels  All parts (especially PMTs) must be rad. hard. Two readout schemes investigated and studied in beam tests: Two readout schemes investigated and studied in beam tests: PMT directly coupled to the Cherenkov tubes (  rad hard tests needed) and fused-silica fibre readout to remote MaPMTs (No rad hard problems) LUCID – The readout LUCID – The readout Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

7. Antonio Zoccoli RICH 2007 – Trieste 7 October 20, 2007 Test Beam Studies - 1 Test Beam Studies - 1 Test beam at DESY (electron beam) : Test beam at DESY (electron beam) : –Nov. `05, –Aug. `06, –Dec. `06. μ = from spectra fit μ = from spectra fit Gas Vessel Tubes read out S1S1 S3S3 S2S2 T1T1 T2T2 BEAM PMT MAPMT

8. Antonio Zoccoli RICH 2007 – Trieste 8 October 20, 2007 Test Beam Studies – PMT readout Test Beam Studies – PMT readout #Photoelectrons using PMT readout: #Photoelectrons using PMT readout: –~70 pe’s/tube from gas at 1 bar –~50 pe’s/tube from PMT window –~120 pe’s/tube TOTAL P1P1 P0P0 P2P2 Npe - (P 1 )~70 Npe - (P 2 )~120 Pressure scan: #Photoelectrons vs gas pressure Pressure scan: #Photoelectrons vs gas pressure

9. Antonio Zoccoli RICH 2007 – Trieste 9 October 20, 2007 #Photoelectrons using fibre readout via Winston cone to remote MaPMT, summing up single fibre yields #Photoelectrons using fibre readout via Winston cone to remote MaPMT, summing up single fibre yields –~12-15 pe’s/tube at 1.25 bar Test Beam Studies – fibre readout Test Beam Studies – fibre readout Central fibres Lateral fibres Middle fibres Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

10. Antonio Zoccoli RICH 2007 – Trieste 10 October 20, 2007 Rad hard tests on PMT HAMAMATSU R762: Rad hard tests on PMT HAMAMATSU R762: – gamma: 60 Co source, E M =1.22 MeV dose: (20±1)MRad  3 year LUCID phase 2 – neutron: ENEA-Casaccia reactor ~100 KeV dose: ~5x10 34 ncm -2  1 year LUCID phase 2 LUCID: PMT rad. hard. tests LUCID: PMT rad. hard. tests Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion No relevant effects for LUCID phase 1 (10 times less than phase 2) No relevant effects for LUCID phase 1 (10 times less than phase 2) gamma neutron

11. Antonio Zoccoli RICH 2007 – Trieste 11 October 20, 2007 PHASE 1 - Low lumi L < ~ 10 33 cm -2 s -1 ends 2009 Dominating sys Final goal ~4-5% +  pp (CDF:~4% ) PHASE 2 – High lumi L ~ 10 34 cm -2 s -1 after 2009 Final goal ~ 2-3% +  pp New project approved. Two different detectors: phase 1 (low lumi) + phase 2 (high lumi) New project approved. Two different detectors: phase 1 (low lumi) + phase 2 (high lumi) Main goal: end of construction in July 2007 Main goal: end of construction in July 2007 LUCID review: installation strategy LUCID review: installation strategy

12. Antonio Zoccoli RICH 2007 – Trieste 12 October 20, 2007 The Design Approved in January The Design Approved in January Fibre RO (4) PMT RO (16) Outer layer ~115 mm rad. Inner layer ~96 mm rad. LUCID approved for installation in ATLAS in January 2007 LUCID approved for installation in ATLAS in January 2007 LUCID construction completed in July 2007 LUCID construction completed in July 2007 Mass = 22 Kg Volume = 54 litres 20 Cerenkov Tubes each end Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

13. Antonio Zoccoli RICH 2007 – Trieste 13 October 20, 2007 The main elements of LUCID produced during the construction phase of LUCID The main elements of LUCID produced during the construction phase of LUCID LUCID Under Construction LUCID Under Construction Gas vessel components LUCID gas vessel under Pressure test PMT Test Facility PMT holders Cerenkov tube manufacture Fibre-optic cable manufacture INBOLOGNA INALBERTA Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

14. Antonio Zoccoli RICH 2007 – Trieste 14 October 20, 2007 LUCID was fully assembled at CERN by an Alberta-Bologna- CERN-Lund team in July 2007 LUCID was fully assembled at CERN by an Alberta-Bologna- CERN-Lund team in July 2007 Test with the LUCID LED pulser system showed all channels were functioning correctly. Test with the LUCID LED pulser system showed all channels were functioning correctly. LUCID Assembled LUCID Assembled Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

15. Antonio Zoccoli RICH 2007 – Trieste 15 October 20, 2007 Alignment to a fraction of a degree to the beam axis required Alignment to a fraction of a degree to the beam axis required Test mounting of alignment system on 3 rd gas vessel in 10/07 Test mounting of alignment system on 3 rd gas vessel in 10/07 The Alignment System The Alignment System Rear alignment system Front alignment system Mods to the VJ cone For LUCID support & alignment system Alignment system pieces Produced at Alberta Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

16. Antonio Zoccoli RICH 2007 – Trieste 16 October 20, 2007 The PMT readout is produced tested and installed (upper photos) The PMT readout is produced tested and installed (upper photos) The MaPMT readout (lower photos) is in a advanced state of readiness. Final commissioning will start as soon as the MAROC3 chip is available next spring The MaPMT readout (lower photos) is in a advanced state of readiness. Final commissioning will start as soon as the MAROC3 chip is available next spring The main LUCID processor VME card (LUMAT) (trigger, data output, on-line lumi measure) is in an advanced state of design – estimated to be ready next spring The main LUCID processor VME card (LUMAT) (trigger, data output, on-line lumi measure) is in an advanced state of design – estimated to be ready next spring LUCID Electronics LUCID Electronics Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

17. Antonio Zoccoli RICH 2007 – Trieste 17 October 20, 2007 So far the move towards installation is on schedule So far the move towards installation is on schedule After the final beam test, presently ongoing @ CERN, we plan to move the LUCID modules into the cavern and test connect them to the available services After the final beam test, presently ongoing @ CERN, we plan to move the LUCID modules into the cavern and test connect them to the available services The final installation of LUCID in the ATLAS forward region is slated for the end of February 2008 The final installation of LUCID in the ATLAS forward region is slated for the end of February 2008 Towards the Installation of LUCID Towards the Installation of LUCID Connect to these resources Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

18. Antonio Zoccoli RICH 2007 – Trieste 18 October 20, 2007 The LUCID design approved at the ATLAS review in January 2007 has been successfully realized The LUCID design approved at the ATLAS review in January 2007 has been successfully realized LUCID was assembled in July 2007 according to schedule LUCID was assembled in July 2007 according to schedule The gas system, the cooling vessel and the alignment system have been designed and are being assembled The gas system, the cooling vessel and the alignment system have been designed and are being assembled The electronics is in an advanced state of readiness and is envisaged to be completely available by Spring 2008 The electronics is in an advanced state of readiness and is envisaged to be completely available by Spring 2008 Extensive beam tests have been performed successfully at DESY. A final test beam at CERN is ongoing, that will enable us to calibrate the LUCID detector(s) Extensive beam tests have been performed successfully at DESY. A final test beam at CERN is ongoing, that will enable us to calibrate the LUCID detector(s) Rad. Hard. Studies have been carried out on the PMT to be installed Rad. Hard. Studies have been carried out on the PMT to be installed The software necessary for the LUCID detector integration in the general MC and for the luminosity monitor is moving on schedule The software necessary for the LUCID detector integration in the general MC and for the luminosity monitor is moving on schedule Remaining – important - detector studies (systematic effects etc.) are in an advanced phase Remaining – important - detector studies (systematic effects etc.) are in an advanced phase We are progressing on schedule and will be ready for installation by December 2007. We are progressing on schedule and will be ready for installation by December 2007. Conclusion Conclusion Forward ATLAS LUCID the basic concept Location LUCID the readout Test beam studies LUCID: rad. hard. tests Installation strategy LUCID design LUCID under construction LUCID assembled The alignment system LUCID: the electronics Installation Conclusion

19. Antonio Zoccoli RICH 2007 – Trieste 19 October 20, 2007 EXTRA SLIDES

20. Antonio Zoccoli RICH 2007 – Trieste 20 October 20, 2007 Use a relatively well known, copious, process: Use a relatively well known, copious, process: Inclusive inelastic pp cross- section Inclusive inelastic pp cross- section large acceptance at small angles large acceptance at small angles µ = avg. # of interactions/b.c.µ = avg. # of interactions/b.c. f = frequency of bunch crossingsf = frequency of bunch crossings  in = tot inelastic cross-section  in = tot inelastic cross-section L = inst. luminosityL = inst. luminosity Use a good estimator Use a good estimator Measure the fraction of crossings with pp interactions Use: prob. of no int. Direct counting # of pp interactions Counting particles Counting hits Cross-calibrate Cross-calibrate Machine information Roman Pots Rarer, clean, better understood physic processes Use dedicated detector: Use dedicated detector: Strategies for lumi measurement Strategies for lumi measurement

21. Antonio Zoccoli RICH 2007 – Trieste 21 October 20, 2007 [ATLAS-LUM-PUB-2006-001] Measured by LUCID Measured by LUCID (at low luminosity  <1) Given by calibration method LUCID with 200 tubes (No Secondaries) Calibration Constant: A =  pp x  inel Run LUCID in parallel with calibration measurement Advantage of “Parallel” Calibration Measured: Not easy at high precision, e.g. CDF vs E811 discrepancy Calculated: Acceptance shown at the Tevatron to be difficult to calculate in forward region Calculated  and measured  tot used for consistency cross checks LUCID calibration strategy LUCID calibration strategy

22. Antonio Zoccoli RICH 2007 – Trieste 22 October 20, 2007 Start up QED: small  QED –pp  (p+  *)+(p+  *)  p+(  )+p Low rate (<< 1 Hz) still at L=10 34 cm -2 s -1 Low rate (<< 1 Hz) still at L=10 34 cm -2 s -1 Process calculated with  1% accuracy Process calculated with  1% accuracy EW: W/Z  leptons EW: W/Z  leptons –Theoretically well understood processes (calculated till NNLO) –High rate:  6Hz for Z    ,  60Hz for W    at L=10 34 cm -2 s -1 Online monitor at high luminosity Online monitor at high luminosity  L / L ) syst ~ 4-6% *;  L / L ) stat ~ 1-5% *  L / L ) syst ~ 4-6% *;  L / L ) stat ~ 1-5% * QCD:  tot ~ 100 mb –Roman Pots at dedicated luminosity (L≈10 27 cm -2 s -1 ) and optic Absolute Luminosity L Absolute Luminosity L –Counting of the number of bunch crossings with/without interaction Online monitor  Relative Luminosity L Online monitor  Relative Luminosity L No Monitor Online * Small statistical error (<1%)  homogeneous samples with at least 10K-100K ev Physics processes Physics processes

23. Antonio Zoccoli RICH 2007 – Trieste 23 October 20, 2007 Cherenkov photons from gas + PMT window Cherenkov photons from PMT quartz window 1 interaction per event Sensitive to IP-pointing tracks above threshold Much shorter paths for non pointing secondaries The response of the detector is linear with both PMT and fiber read-out LUCID performances LUCID performances

24. Antonio Zoccoli RICH 2007 – Trieste 24 October 20, 2007 During beam pipe bake out LUCID could reach ~250 o C During beam pipe bake out LUCID could reach ~250 o C A cooling system must be employed to keep the temperature of LUCID well below 50 o C (PMT specs.) A cooling system must be employed to keep the temperature of LUCID well below 50 o C (PMT specs.) This is achieved using a water cooled aluminium cylinder using 6 copper cooling loops (20 litres/hr in each loop) This is achieved using a water cooled aluminium cylinder using 6 copper cooling loops (20 litres/hr in each loop) FEA shows that the temperature of the inner radius will be maintained at a temperature of ~20 o C using this jacket (assuming perfect connection between cooling pipe and Al) FEA shows that the temperature of the inner radius will be maintained at a temperature of ~20 o C using this jacket (assuming perfect connection between cooling pipe and Al) The cooling system in currently under fabrication in Alberta The cooling system in currently under fabrication in Alberta The LUCID Cooling System The LUCID Cooling System The cooling cylinder deployed Between the beam pipe and LUCID Cooling system under fabrication at Alberta (Heat dissipated during beam Pipe bakeout is 250 W/m)

25. Antonio Zoccoli RICH 2007 – Trieste 25 October 20, 2007 No continuous flow of C 4 F 10 No continuous flow of C 4 F 10 Pressure maintained (at 1.25/1.5 Bar by regulator) leak rate observed less than 10 millibar/day Pressure maintained (at 1.25/1.5 Bar by regulator) leak rate observed less than 10 millibar/day Front PanelSchematic of Gas System The LUCID Gas System The LUCID Gas System

26. Antonio Zoccoli RICH 2007 – Trieste 26 October 20, 2007 Test beam venue - SPS H8 in Prevessin Test beam venue - SPS H8 in Prevessin Test Beam period 18 th  28 th of October 2007 Test Beam period 18 th  28 th of October 2007 Final assembly of additional components of LUCID for beam test in b154 ( mechanical cage) from the 10 th to the 15 th of October Final assembly of additional components of LUCID for beam test in b154 ( mechanical cage) from the 10 th to the 15 th of October Next – Test-Beam in Oct. 2007 (1) Next – Test-Beam in Oct. 2007 (1)

27. Antonio Zoccoli RICH 2007 – Trieste 27 October 20, 2007 Next – Test-Beam in Oct. 2007 (2) Next – Test-Beam in Oct. 2007 (2) Main goal: calibrate 40 tubes (PMT+MAMPT-with DESY 12/2006 system-) i.e. # p.e./track Main goal: calibrate 40 tubes (PMT+MAMPT-with DESY 12/2006 system-) i.e. # p.e./track Determine optimum gas pressure for LUCID running Determine optimum gas pressure for LUCID running The moveable table The area in which the table will be placed table will be placed The beam dump region

28. Antonio Zoccoli RICH 2007 – Trieste 28 October 20, 2007 Integration in the ATLAS MC Integration in the ATLAS MC THEGEOMODELTHEGEOMODEL Our stand-alone Monte Carlo predicts satisfactory LUCID performance. We have started the process of integration of the LUCID into the ATLAS MC Our aim is to be ready for the Full Dress Rehearsal by the end of 2007

29. Antonio Zoccoli RICH 2007 – Trieste 29 October 20, 2007 The LUCID Data Flow The LUCID Data Flow

30. Antonio Zoccoli RICH 2007 – Trieste 30 October 20, 2007 Radiation Hardness A Hamamatsu R762 photomultiplier has been irradiated with a 60 Co source and the dark current and gain has been studied. PMT 2: No irradiation PMT 1: 20 MRad in 18 hours Equivalent to 15 years at 2x10 33 cm -2 s -1 Equivalent to 3 years at 1x10 34 cm -2 s -1 The increase of the dark current is not a concern for the PMT lifetime ! V. HedbergATLAS Overview Week - 20.02.2007 18

31. Antonio Zoccoli RICH 2007 – Trieste 31 October 20, 2007 Radiation Hardness Before irradiation ! No irradiation ! After 20 MRad No irradiation ! V. HedbergATLAS Overview Week - 20.02.2007 19

32. Antonio Zoccoli RICH 2007 – Trieste 32 October 20, 2007 The readout scheme

33. Antonio Zoccoli RICH 2007 – Trieste 33 October 20, 2007 Scalers in the Trigger Card (Firmware) for Online Luminosity LUCID ALUCID C II. Particle Counting I. Collision/Zero Counting 16 tubes 1 2 3 4  4 x 3564 x 32bit ~ 60kB (1-4 x BCIDs x Scaler depth) 1 2 (If LUCID A-C Coincidence) 3 4 (If LUCID A-C Coincidence)  4 x 3564 x 32bit ~ 60kB III. Total Orbit Counter For normalization (Average) All scalers start/stop are synchronized with the Orbit signal to scale over the same interval at a BC precision Scalers are incremented on L1A (for dead time correction) Scalers read-out by VME and sent to DCS (~ 120 kB for each Luminosity Block –few min-) for processing, to be published at any time  32bit

34. Antonio Zoccoli RICH 2007 – Trieste 34 October 20, 2007 The important steps in the LUCID assembly sequence followed in July 2007 The important steps in the LUCID assembly sequence followed in July 2007 The Assembly of LUCID The Assembly of LUCID LUCID the basic concept Location Test beam studies LUCID design LUCID under construction Assembly LUCID assembled The alignment system The cooling system The gas system Next test beam MC integration Installation Conclusion