1. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment1 LHCf - an experiment for measuring the very forward production of neutral particles at the LHC W.C. Turner LBNL for the LHCf Collaboration Presented at the Aspen Workshop on Cosmic Rays 15-19 Apr 2007

2. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment2 The LHCf Participants Nagoya University, Japan K. Fukui, Y. Itow, T. Mase, K. Masuda, Y. Matsubara, H. Matsumoto, H. Menjo, T. Sako, K. Taki, H. Watanabe Kanagawa University, Japan T. Tamura Konan University Y. Muraki (Spokesperson), Waseda University, Japan K. Kasahara, Y. Shimizu, S. Torii Shibaura Inst. of Tech., Japan K. Yoshida University of Florence, Italy O. Adriani, L. Bonechi, M. Bongi, G. Castellini, R. D’Alessandro, P. Papini University of Catina, Italy A. Tricomi Univerity of Valencia, Spain A, Faus-Golffe, J. Valesco CERN, Switzerland D. Macina, A.-L. Perrot Ecole-Polytechnique Palaiseau, France M. Hauguenauer Lawrence Berkeley Laboratory, USA W.C. Turner

3. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment3 Outline Motivation and History of LHCf The LHC Environment The LHCf Detectors Anticipated LHCf Performance SPS Beam Test and Monte Carlo Results Installation and Schedule

4. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment4 Motivation and History Use 7+7 TeV pp collisions to benchmark neutral particle production cross sections at 10 17 eV laboratory equivalent energy –Useful for cosmic ray simulations, contribute to resolution of super GZK and composition questions Previous experiment UA7 performed at SPPS 400 + 400 GeV, 10 14 eV (E. Pare et al, Phys. Lett., B242 (1990)) Present Experiment LOI submitted to LHCC in May 2004 and TDR approved in 2006 Prototype detector tested at SPS H4 in 2004 and final detector in 2006 First detector installed at IP1 in Jan 2007

5. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment5 The LHCf detectors are located +/-140m from IP1 in LHC IP1, ATLAS, LHCf IP5, CMS IP2, ALICE IP8, LHCb

6. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment6 Interaction region The TAN absorbs forward neutral collision products (mostly neutrons and photons) and is placed in front of the outer beam separation dipole D2 to protect superconducting magnets LHCf exploits the opportunity to install detectors inside the TAN for measurement of very forward neutral particle production cross sections TAN neutral particle absorber

7. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment7 Exploded view of the TAN and transition beam tube IP, +140m Instrumentation slot (96mm x 60.7mm x 1000mm) ~ 5m

8. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment8 Measure 100 GeV - 7 TeV gammas and neutrons Detectors are located on both sides of IP1 (Arm#1 and Arm#2) for coincidence studies and redundancy Each Arm consists of two “tower” calorimeters for separately measuring the two gammas from  0 decay - 44 radiation lengths of W plates interleaved with 16 scintillation panels (overall length 25cm) - Transverse cross sections 20mm x 20mm + 40mm x 40mm Arm#1 and 25mm x 25mm + 32mm x 32mm Arm#2 Four position sensitive layers measure the transverse center of the showers - Arm#1 SciFi (1mm x1 mm) - Arm#2 Si microstrip detectors(80  m pitch) The LHCf detectors are compact sampling and imaging calorimeters

9. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment9 LHCf tower calorimeter illustrations Arm#1Arm#2 W plates Scintillator SciFi x-y layerSi microstrip x-y layer 25cm

10. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment10 Arm#1 during assembly Tower calorimeters Light guides 32 PMTs + 8 MAPTs

11. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment11 Transverse projection of LHCf and beam pipe acceptance

12. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment12 LHCf Arm#1 acceptance “450  rad” 140  rad xing angle “310  rad” 0  rad xing angle

13. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment13 PMT + scintillator linearity ~+/- 2% over anticipated dynamic range Dynamic range req’d: 1 mip (muon calibration of light collection efficiency) to 7x10 4 mips (7 TeV gamma shower max) “mips” simulated with Nitrogen Laser excitation of scintillator

14. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment14 The LHCf team for 2006 SPS Beam Tests

15. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment15 SPS H4 Setup

16. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment16 BeamEnergy(GeV)Measurements Electron beam 50, 100, 150, Simulate photon showers, 200 measure energy resolution, spatial resolution and shower leakage Proton beam 150, 350Simulate neutron showers Muon beam 150 Obtain calibration for single mip, measure non-uniformity of light collection efficiency SPS test beam 2004 results

17. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment17 Light efficiency correction measured with a muon beam

18. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment18 Shower leakage, energy resolution, SPS data +MC Fig. 7 MC simulation, include it?

19. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment19 MC simulation shows the shower leakage fraction is energy independent

20. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment20 Position resolution

21. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment21 e-p/  -n separation LHCf = 44rad lengths, 2 hadron interaction lengths L20-90 = discrimination parameter = distance between 20% and 90% of longitudinal sum of shower particles

22. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment22 MC calculations of  0 mass and neutron energy resolutions  0 inv mass res ~ 5% Neutron energy res ~ 30%

23. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment23 Arm#1 pre-installed Jan 07, Arm#1&2 final installation ~ Sep 07 IP1 140m away TAN LHCf Arm#1

24. LHCf Aspen Workshop on CRP, 15-19 Apr 2007 W.C. Turner – The LHCf Experiment24 Plans for future operation with LHC “450 x 450 GeV Engineering Run” ~Oct - Dec 2007 (Could get delayed to 2008 owing to inner triplet problems! Will know in mid- May.) – Observe first pp collisions and background rates due to beam-gas, beam halo collisions etc – Low event rates owing to reduced acceptance,  single  >10GeV ~20Hz   0 reconstruction below background “Stage 1” 7 TeV x 7 TeV beam commissioning~Jun - Sep 2008 – Luminosity ~10 29 cm -2 s -1, inelastic collision rate ~ 8kHz – 43 x 43 bunches => 2  sec bunch spacing matches max DAQ rate – Single  >100GeV rate ~ 800Hz – Two   0 rate ~ 80Hz(10 6 events in 3.5 hrs) – Two arm coincidence ~ 80Hz – Neutrons >100GeV ~ 4kHz – Remove LHCf when Luminosity > 10 30 cm -2 s -1 to avoid rad. damage