A magnetized muon spectrometer for ICARUS T3000

1. A magnetized muon spectrometer for ICARUS T3000

2. ICARUS COLLABORATION 25 INSTITUTIONS, 150 PHYSICISTS CNGS2 EXPERIMENT • ICARUS experiment jointly approved by INFN and CERN • CNGS2 (April 2003) • Explicit search for n oscillations at the CNGS neutrino beam

3. Liquid Argon TPC ICARUS T300 prototype • Many years of R&D • Prototypes at lab scale • T600 detector • Technical run on surface (Pavia, Aug 2001) • Detector performed as expected • Demonstration that LAr technique is mature and can be used to build very massive detectors matching requirements imposed by neutrino physics and proton decay searches Inner detector view

4. Cosmic Ray Data • More than 27000 triggers collected during technical run • Testing 3D reconstruction, particle ID capabilities, … • Publications so far… • Design, construction and tests of the ICARUS T600 detector, submitted for publication by NIM A on 31/12/03. • Measurement of the muon decay spectrum with the ICARUS T600 liquid Argon TPC, accepted for publication on European Physics Journal C on 1/7/2004. • Study of electron recombination in liquid Argon with the ICARUS TPC, accepted for publication on NIM A on 30/10/03. • Analysis of Liquid Argon Purity in the ICARUS T600 TPC, Nucl. Inst. Meth. A516 (2004) 68-79. • Observation of long ionizing tracks with the ICARUS T600 first half-module,Nucl. Inst. Meth. A508 (2003) 287-294.

5. Michel Electron Spectrum • Study of stopping muon sample • 3000 events analyzed and fully reconstructed in 3D • r parameter measurement • Standard Model r = 0.75 • Energy resolution for electrons below ~50 MeV • Accepted for publication Eur. J. Phys C

6. Multi-Muon Events Zenith Angle • On going analysis • Allows to study detector response ( spatial resolution, uniformity, energy calibration) • Capability to distinguish narrowly spaced muons Multiplicity

7. First Unit T600 + Auxiliary Equipment T1200 Unit (two T600 superimposed) T1200 Unit (two T600 superimposed) T3000 Detector • A Second-Generation Proton Decay Experiment and Neutrino Observatory at Gran Sasso Laboratory • Construction strategy: “Cloning” the successfully operated T600 module • T300 = T600 + T1200 + T1200 3 Ktons of Liquid Argon LNGS Hall B

8. A Rich Physics Programme • Atmospheric, Solar and Supernova neutrinos • Background-free proton decay searches • Long Baseline Neutrino Experiment • CERN-Gran Sasso LBL experiment already proposed by the collaboration back in 1993 • Excellent granularity and particle ID allows to measure and classify all final events • nm CC, ne CC, nt CC , n NC • Most important Physics issues at CNGS: Explicit search for nmnt and nmne

9. Super-Kamiokande: 1.6 < Dm2 < 4.0 at 90% C.L. CNGS: nmnt Oscillations 18% 18% 50% 14% nt+Art+jet; t • Main reaction • Search based on kinematical criteria • Natural nt contamination below 10-7 w.r.t. nm component • Several decay modes investigated (electron decay is the “golden” channel) • 5 years of CNGS operation (4.5 x 1019 p.o.t.) • T3000 detector (2.35 kton active LAr, 1.5 kton fiducial)

10. CNGS: nmne Oscillations • Main reaction • Natural ne contamination 1% • Limited by CNGS statistics ne+Are-+jet; For Dm223 = 2.5 x 10-3

11. Physics motivations for a muon spectrometer at CNGS (I) • In 1999, we already proposed to complement LAr with an external magnetize device to measure escaping muons • Main motivations (SPS-P-323-Add 1) • The nmnt search is based on kinematical technique • nm CC events used as a high statistics control sample • 32600 events after five years of data taking • Study nuclear effects at the neutrino interaction vertex • The study of the kinematical closure of these events requires a precise enough measurement of the leading muon in order to be sensitive to the kinematical feature of the recoiling jet, namely of the order of  p/p ≈ 20%. • A large majority of leading muons escape the active LAr volume  An external spectrometer is mandatory

12. Physics motivations for a muon spectrometer at CNGS (II) • The nmne search is based on search for an excess of electron neutrino signal over the intrinsic beam contamination • precise prediction of the parent meson yields and hence of the various neutrino flavor components at LNGS can be largely improved by a precise and independent in-situ measurement of the energy spectrum of the nm and anti-nm fluxes and by a good sensitivity to the high energy tail (typically En>50 GeV) where muon neutrinos come primarily from kaon decays • Muon charge discrimination and measurement in the neutrino energy range 50 < En < 100 GeV requires an external magnetic analysis of the leading muons 10% of nm CC events have En > 50 GeV

13. ne Beam Component Prediction Preliminary estimate (Guglielmi et al., INFN note):systematic error 3% on ne/nm

14. T600 T1200 T1200 Muon Spectrometer ICARUS T3000 + Muon Spectrometer LNGS-EXP 13/89 Add. 3/03 CERN/SPSC 2003-030 SPSC-P-323-Add. 1

15. LAr RPC PDT Fe GEANT 4 Full Simulation Baseline Design • Simultaneous optimization of Physics performance and cost • Simplest solution (known technology, no R&D needed) • Passive material: Magnetized non-instrumented iron • B=1.8 T • Cross Section: 8.5 x 8.5 m2, two bending sections 1.5 m long each • Sensitive part: Planes of proportional drift tubes • External device to provide trigger: RPC (precise t0 measurement)

16. Expected Muon Momentum Resolution spoint = 300 mm spoint = 600 mm ( 13 ns) Resolution around 17% Estimated wrong sign contamination 10-3 -10-4 spoint = 1 mm ( 20 ns)

17. Beam Profile Measurement One year data taking 1800 events After one year, precise measurement of the CNGS beam profile Average neutrino energy resolution around 7%

18. ICARUS MAGNET ICARUS Magnet

19. ICARUS Magnet ICARUS Magnet

20. Magnet Basic Parameters MAGNET COIL ELECTRICAL PARAMETERS

21. Basic Drift Cell Design CMS final design Possibility to build simplified cell for ICARUS under study Resolution grows up to 300 mm  Dpm/pm ~16% • Gas composition: 85% Argon, 15% CO2 • High Voltage Operation: • Anode: 3.6 kV • Cathode: -1.2 kV • Electrode Strips: 1.8 kV • Drift Velocity: ~ 55 mm/ms • Max drift: ~ 350 ns • Resolution: ~ 200 mm

22. Basic Muon Chamber

23. Precision Table I beams ready to be glued CIEMAT’S Assembly Hall • Spanish group involved nowadays in construction of muon chambers that instrument CMS Barrel

24. Chamber Assembly Bottom Al plate with I-beams Automatic glue dispenser Central electrodes & wire positioning Glue Al lid on top Layer final layout Al plates I-beam Wire

25. CMS Chamber Construction ICARUS production will proceed once CMS chamber construction is over (2005)

26. Alignment System • Rasnik/CCD (L3) • Tilt meter • Laser micrometers • Straight muons O(1)/m2/day (B off)

27. Installation: Schematic view

28. Installation Procedure

29. Preliminary Time Scale for Installation

30. Conclusions • An external muon spectrometer is a MUST in order to exploit fully the Physics capabilities of a LAr detector (CNGS2) at the CERN to Gran Sasso Neutrino Beam • On-line beam energy spectrum monitoring • Assessment of event kinematics reconstruction • Beam composition • Precise measurement of ne contamination • The baseline design is simple and based on known detection techniques • No R&D needed • Easy to build, install and operate