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LHCf Status Report

LHCf Status Report. Oscar Adriani. Outline. Status of the experiment Hardware/DAQ/Software/Simulation Activity in 2008/2009 Radiation damage Simulation Dosimeter installation Running strategy for 2009/2010 and for the future LHCC Atlas LHC Program Coordinator Hardware modifications?.

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LHCf Status Report

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  1. LHCf Status Report Oscar Adriani

  2. Outline • Status of the experiment • Hardware/DAQ/Software/Simulation Activity in 2008/2009 • Radiation damage • Simulation • Dosimeter installation • Running strategy for 2009/2010 and for the future • LHCC • Atlas • LHC Program Coordinator • Hardware modifications? Oscar Adriani CSN1 17/09/09

  3. LHCf for newcomers (only 1 slide..) Detector I Tungsten Scintillator Scintillating fibers Detector II Tungsten Scintillator Silicon mstrips INTERACTION POINT IP1 (ATLAS) 140 m 140 m Beam line • Measurement of g and p0 energy spectra at Zero Degrees • Important for cosmic ray physics • 7+7 TeV in the center of mass  1017 eV in the lab system • Crucial region for cosmic ray physics • Calibration of Monte Carlo codes and hadronization • models Oscar Adriani CSN1 17/09/09

  4. Status of the experiment: hardware • LHCf Arm1& Arm2 ready in the tunnel since 2008 • Only ‘minor activities’ in the tunnel and counting rooms: • Tunnel: • New 220 V plugs in the tunnel • Front Counter improvement • Remote handling installation (important for the future!!!!) • Counting rooms: • Better setup of the 2 small ‘Counting rooms’ (barraques…) • New PCs • UPS • Improvement of the laser calibration system stability (to reach 2% long term stability) Oscar Adriani CSN1 17/09/09

  5. Stability result for Arm1 Tower0 (24/08 – 07/09) Blue line shows ±1% 90% of PMT shows <2% stability Oscar Adriani CSN1 17/09/09

  6. Status of the experiment: DAQ & Online analysis • Test of new Pace3 parameters to increase dynamics • Some modifications to the DAQ software • Avoid polling of VME bus to detect trigger (Noise induced in the Low Threshold Discriminator) • Slow control system (also for DIP signals) • Fast analysis framework • Online monitor to control the ‘phyiscs related aspects’ • Alert messenger to detect basic problems • Power supply problem • VME problem • Data corruption problem Oscar Adriani CSN1 17/09/09

  7. Status of the experiment: Simulation and physics • Work done in the last months: • Fluka/Epics comparison • Background estimate • Particle identification • MC at different energies (very important for dose related stuff!  see later) • p0 analysis Oscar Adriani CSN1 17/09/09

  8. Gamma2 E2+E’1 Gamma1 E1 p0 measurement (paper submitted to Astroparticle Physics) • Reconstruction method • Mass, energy and momentum of p0 are reconstructed from energy and incident position of gamma-ray pair measured by the two calorimeters. • Energy reconstruction for gamma-ray • Correction of shower “leak-in” • Incident position • Event selection • Multi-hit cut, • PID cut, • Reconstructed mass cut. Oscar Adriani CSN1 17/09/09

  9. Survival efficiency p0 energy resolution 3% @ 1TeV Oscar Adriani CSN1 17/09/09

  10. Model discrimination capability (1000 sec runs) Systematic effects taken into account: • Uncertainty of Multi Hit contamination (model dependence) • Uncertainty of energy scale ：　assumed as ±5% • Uncertainty of relativistic number of events between 2 pos. <0.1% • Uncertainty of neutral beam center<0.1％ Oscar Adriani CSN1 17/09/09

  11. Radiation damage studies • Radiation damage study is very important for LHCf • Plastic scintillator starts to degrade at 10 Gy 100 Gy 1000 Gy 10 Gy Oscar Adriani CSN1 17/09/09

  12. Dose vs Beam Energy • Extensive study of expected dose on LHCf plastic scintillators as function of beam energy has been done in the last few months • These info have been shared with BRAN people!!! • Full simulation for 450 GeV, 3 TeV, 5 TeV, 7 TeV (DPMJET-III): • Particle generation in the IP • Particle transport towards TAN • Shower development in the calorimeter • Study of dose integrated by scintillator in the various layers • Study of dose as function of vertical position (garage) Oscar Adriani CSN1 17/09/09

  13. Dose estimation at 7+7 TeV Lumi=1029cm-2s-1 2.5×10-2 Gy/100sec 40mm calorimeter 20mm calorimeter Please note: 100 s at 1029cm-2s-1 0.01 nb-1 Oscar Adriani CSN1 17/09/09

  14. Position dependence of Radiation Damage • Previous estimation is average dose in each scintillator • The position dependence has also been obtained 7+7 TeV • The maximum point is 1.6 times larger than average Oscar Adriani CSN1 17/09/09

  15. Results on radiation damage The dose approximately scale as E3 3.5 TeV Monte Carlo is running now. Results will come before next LHCC (23/09) Oscar Adriani CSN1 17/09/09

  16. Energy flux in front of LHCf detector Energy flux for 7TeV 3 orders of magnitude reduction in dose from running to garage positions GeV/s/cm2 Oscar Adriani CSN1 17/09/09

  17. Dosimeter installation • The knowledge of the real dose integrated by LHCf is very important • Install dosimeter very close to the detector! • CERN developed RADMON dosimeter system and online readout (real time) Remote measurement unit <5 mm thick if we remove box and connector 2 additional new RADMON v.5 dedicated to LHCf under each TAN have already been installed • 2 quantitative measurements in the remote unit: • Total Ionising Dose (TID) – MOS Radfet (<200Gy,<2KGy,<20KGy) • 1 MeV equivalent neutrons fluence [n/cm2] – PIN diodes • Data are sent online and accessible real time on the CERN network Oscar Adriani CSN1 17/09/09

  18. Where to install dosimeter? • There is a 7 mm slot between LHCf back end and BRAN-IC front end • Dosimeter will move up and down together with LHCf to precisely know the integrated dose! LHCf BRAN IP 7 mm gap Oscar Adriani CSN1 17/09/09

  19. Original LHCf running plan (summary of many past years slides…) • The detector has been designed for low luminosity/high energy beam (see LOI, TDR): • Optimal Lumi  1029cm-2s-1 • Maximum Lumi < 1031cm-2s-1 • Energy = 7+7 TeV • The detector should take data in the first LHC phase, at low luminosity and high energy • The detector is removed once Lumi is too high • The detector will come back in dedicated low luminosity future runs • Crossing angle to improve the acceptance • Heavy/Light ions? Oscar Adriani CSN1 17/09/09

  20. Atlas e.m. ZDC or LHCf Running strategy (NEW!!!) • Due to dramatic change of the LHC schedule, define the best running strategy is the MOST IMPORTANT point now for LHCf! • The incident of LHC caused us many troubles • Big delay • We were ready at very beginning! • Atlas e.m. ZDC were not ready, they will be ready at December 2009 • Change in the machine plans • Low energy soon (3.5 TeV) • Higher energy later (5 TeV) • Highest energy (7 TeV) when??? • High luminosity also at low energy • Interference with BRAN • Radiation damage • Possible improvement of the detector? Oscar Adriani CSN1 17/09/09

  21. Memo to LHCC Page 3 Page 1 Oscar Adriani CSN1 17/09/09

  22. BRAN Interference • Dose reduction by 3 orders of magnitude in the garage position • But…. No signal from BRAN-IC if LHCf is not on the beam!!!! Oscar Adriani CSN1 17/09/09

  23. BRAN Interference • BRAN-IC is anyway not well performing if L<1031 cm-2 s-1 • BRAN-Sci is working for low luminosity, and is not affected by the LHCf position • Agreement reached at LTEX (June 2009): • BRAN-Sci is used at low luminosity and when LHCf is in garage • Since BRAN-Sci is radiaton weak, it should be replaced when it will be radiation damaged • LHCf will contribute to pay for spare BRAN-Sci Oscar Adriani CSN1 17/09/09

  24. Discussion with LPC • Collaborative discussions under way with Massimiliano Ferro Luzzi, to find a solution that satisfy both LHCf and Atlas • Atlas is worried for 2 reasons: • ZDC e.m. are ‘almost ready’ (December?) • BRAN-Sci is not as good as BRAN-IC to set-up the beam? • A possible ‘solution’ (still to be agreed): • LHCf takes data at 3.5+3.5 TeV, until Lumi is too high (see Lamont presentation) • LHCf goes out and Atlas e.m. ZDC goes in • LHCf comes back in the TAN for 5+5 TeV • When? During 2010 or at beginning 2011? • Meanwhile improve radiation resistance of plastic scintillators and/or change the silicon layer distribution/number Oscar Adriani CSN1 17/09/09

  25. M. Lamont, LHC 2009/2010 running scenario, September 2009 Oscar Adriani CSN1 17/09/09

  26. Some possible scenarios Scenario 1 LHCf preferred Scenario 2 Scenario 3 Atlas preferred Based on the dates for 2009/2010 from Lamont, should be rescaled according to schedule change Oscar Adriani CSN1 17/09/09

  27. Improve the radiation resistance of LHCf Basic idea: • The existing LHCf is fine for low luminosity • Many difficulties due to LHC, Atlas, BRAN etc. • To be in a safer position the LHCf collaboration started a discussion how to improve the radiation resistance of the detector • Data taking at all energies • 7+7 TeV later on…. At high lumi! Oscar Adriani CSN1 17/09/09

  28. Selection of candidate scintillators Requirements for the new scintillators • Rad-hard  generally, crystal scintillators • Emission wave length matches with PMTs • Decay constant ~10 nsec (not too fast for PMT saturation, not too long to avoid have long tail for overlap) • Machinable to 40x40x(1-3)mm3 with sufficient precision • Reasonable price and delivery time • Can be excited by the existing N2 laser system Two candidates GSO and PWO are studied. Oscar Adriani CSN1 17/09/09

  29. Property of 2 candidates • GSO • Emission; 440nm (peak) • Decay constant; 30-60ns • Rad hardness (definition to be checked); 106-7Gy • Laser; OK • Yield; 10,000 photons/MeV • Price; expensive! 700-800 CHF/piece • PWO • Emission; 430nm (peak) • Decay constant; 2.1, 7.5, 26ns (3 components) • Rad hardness; 104-5Gy • Laser; to be tested • Yield; generally very small (to be tested) • Price; very cheap! 90CHF/piece • Limited <30mm (surveying other factory) • Temperature dependence? • Some samples are already available in Nagoya and being tested Advantage Disadvantage Oscar Adriani CSN1 17/09/09

  30. GSO with N2 laser 337nm laser • GSO transmits 337nm • GSO is excited by 337nm • FWHM is ~25ns Oscar Adriani CSN1 17/09/09

  31. Japan money Supplementary budget from Japan government is approved  GSO can be selected. ~7MYen/50K€ can be used for upgrade. All cost for GSO scintillator tiles (~5MYen/30K€) can be covered. Because there is so far no demerit known in GSO except cost, we should investigate more realistic and technical procedure for upgrade with GSO. Oscar Adriani CSN1 17/09/09

  32. GSO Thickness • 3mm GSO = 0.22 X0 (plastic: 0.007 X0) • Shower structure changes from current design • Too much light yield, slightly much cost • 1mm GSO = 0.07 X0 • Small shower modification from current design • (maybe) sufficient yield and better cost • Still machinable, but (maybe) fragile when connected with acrylic light guide and fibers • How to fit with the current 3mm G10, delrin holders? 1 mm is preferable  solve technical issue Oscar Adriani CSN1 17/09/09

  33. Modifications of silicon part • Basic idea • In the ‘original’ LHCf silicon part is only used to measure the impact point • But… it can be used as a cross check for energy scale!!!!! • How can we optimize the distribution of existing silicon layers (4 X and 4 Y) to measure the energy???? • Should we increase the number of silicon layers to improve the energy resolution??? Oscar Adriani CSN1 17/09/09

  34. ARM2-Silicon Energy Resolution 200 GeV electrons SPS beam test data DE/E ~ 12% Presented at Pisa CSN1 last year! Total energy measured in silicon (ADC) By looking only at the silicon energy measured, we have an energy resolution ~ 10%!!!!! We can use it as a check for the radiation damage of the scintillators Oscar Adriani CSN1 17/09/09

  35. X,Y X,Y X,Y X,Y Y X Y X Y X Y X Optimization of silicon layer positions for energy reconstruction Silicon layer positions in the current Arm2 detector. Distribute 8 silicon layers. Geometrical configuration of this simulation study Silicon layers are inserted at the front of all scintillator layers. For energy reconstruction, we sum dE of all scintillator layers,2, 8 and 16 of the 16 silicon layers. Oscar Adriani CSN1 17/09/09

  36. Hit Position dE at each scint. layer Sum of dE at each silicon layer Event view (1): Good event 100GeV Gamma-ray hits near the center of the 25mm calorimeter Oscar Adriani CSN1 17/09/09

  37. Hit Position dE of Shower leakage particles Event view (2): Problematic event 100GeV Gamma-ray hits near the edge of the 25mm calorimeter. Oscar Adriani CSN1 17/09/09

  38. Y X Uniformity of Sum(dE) Map of sum(dE) of Si Map of sum(dE) of Scin. Map(Si) / Map(Scin.) The silicon layers have more dE than scintillator layers due to additional dE by particles leaking out from the calorimeters. The difference increases near the top and left edges. Oscar Adriani CSN1 17/09/09

  39. Energy Resolutions for g Good energy resolution of the silicon layers !! Hit Position Selection Preliminary!!!!! 4<x<20, 4<y<20 Oscar Adriani CSN1 17/09/09

  40. Energy Resolutions for g with a tighter hit position cut Dominant sources of the resolution are • Scintillator , Silicon (8,16)  position dependence, • Silicon (current configuration)  shower fluctuation. Hit Position Selection Preliminary!!!!! 8<x<11, 8<y<11 Oscar Adriani CSN1 17/09/09

  41. Conclusions • Handling all the technical and political aspect of the LHCf running is not trivial… Big effort from all the collaboration • It seems that we have support from LPC and LHCC • We are trying to find a solution that is acceptable both from LHCf and ATLAS • Meanwhile we are working for a safer future: • GSO • New silicon layer structure (INFN CSN1 will certainly be kept informed!) • I did not mention that a long and detailed (50 pages) technical paper on the silicon part is ready to be submitted to JINST Oscar Adriani CSN1 17/09/09

  42. Oscar Adriani CSN1 17/09/09

  43. Oscar Adriani CSN1 17/09/09

  44. Dose estimation as function of vertical position Gy/100s h/10Gy Gy/h 0.04 1.14 6.94 7TeV w/ pipe 7TeV w/o pipe 5TeV w/o pipe 1TeV w/o pipe 450GeV w/o pipe 450GeV w/ pipe In garage 3 orders of magnitude reduction Oscar Adriani CSN1 17/09/09

  45. ATLAS ZDC memorandum Oscar Adriani CSN1 17/09/09

  46. Crystal scintillators Wavelength 350-600nm Decay constant 10 - a few 10 nsec Rad hardness >103Gy = 105 Rad No hydroscopic Oscar Adriani CSN1 17/09/09

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