ICARUS and the status of LAr technology Carlo Rubbia LNGS-Assergi, Italy CERN, Geneva, Switzerland 1
History: a Gargamelle neutrino event Charm production in a neutrino interaction The total visible energy is 3.58 GeV.
The path to massive liquid Argon detectors CERN 6 2010: ICARUS Operational 1 in Hall B of LNGS 2 Laboratory work CERN 3 CERN T600 detector 2001: First T600 module 4 20 m 5 Cooperation with industry Japan_Dec 2010 Japan_Dec 2010 Slide# : 3 Slide# : 3
Early neutrino physics at CERN_WANF(1997-98) ● Quasi-elastic events with a 50 litres LAr TPC in front of NOMAD: a quasi-elastic neutrino event; a multi-prong neutrino event reconstructed in 3D Japan_Dec 2010 Japan_Dec 2010 Slide# : 4 Slide# : 4
Reconstruction of Quasi-elastic LAr events ● Quasi-elastic neutrino events in LAr have been reconstructed in the 50 litre ICARUS LAr-TPC exposed to the CERN-WANF beam in coincidence with the NOMAD experiment. ● Simulations, accounting for Nuclear Fermi motion and re- interactions in nuclei, are found in good agreement with a 200 pure lepton-proton final state events with 1 proton TP > 50 MeV (range > 2 cm) and any number protons TP< 50 MeV. Japan_Dec 2010 Japan_Dec 2010 Slide# : 5 Slide# : 5
The ICARUS Collaboration A. Ankowski, K. Graczyk, C. Juszczak, J. Sobczyk Wroclaw University of Technology, Wroclaw, Poland M. Antonello, P. Aprili, N. Canci, C. Rubbia, E. Segreto, C. Vignoli Laboratori Nazionali del Gran Sasso dell’INFN, Assergi (AQ), Italy B. Baibussinov, M. Baldo Ceolin, S. Centro, D. Dequal, C. Farnese, A. Fava, D. Gibin, A. Guglielmi, G. Meng, F. Pietropaolo, F. Varanini, S. Ventura Dipartimento di Fisica e INFN, Università di Padova, Via Marzolo 8, I-35131 A. Cesana, A. Ferrari, P. Sala, A. Scaramelli, M. Terrani Dipartimento di Fisica e INFN, Università di Milano, Via Celoria 2, I-20123 L. Berzè, P. Benetti, E. Calligarich, R. Dolfini, A. Gigli Berzolari, A. Menegolli, C. Montanari, A. Rappoldi, G. L. Raselli, M. Rossella Dipartimento di Fisica Nucleare,Teorica e INFN Università di Pavia, Via Bassi 6, I-27100 F. Carbonara, A. G. Cocco, G. Fiorillo Dipartimento di Scienza Fisiche, INFN e Università Federico II, Napoli, Italy K. Cieslik, A. Dabrowska, M. Szarska, D. Stefan, T. Wachala, A. Zalewska H. Niewodniczanski Institute of Nuclear Physics, Krakow, Poland G. Mannocchi, L. Periale, P. Picchi, Laboratori Nazionali di Frascati (INFN), Via Fermi 40, I-00044 A. Dermenev, S. Gninenko, M. Kirsanov INR RAS, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia J. Holeczek, J. Kisiel, T. Szeglowski University of Silesia, 12 Bankowa st., 40-007 Katowice, Poland D. Kielczewska, M. Posiadala Warsaw Univeristy, Krakowskie Przedmiescie 26/28, 00-927 Warszawa, Poland T. Kozlowski, J. Lagoda, P. Mijakowski, T. J. Palczewski, P. Przewlocki, E. Rondio, J. Stepaniak, M. Szeptycka A. Soltan Institute for Nuclear Studies, 05-400 Swierk/Otwock, Poland W. Polchlopek AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland F. Sergiampietri Dipartimento di Fisica, Università di Pisa, Largo Bruno Pontecorvo 3, I-56127 R. Sulej, K. Zaremba Univeristy of Technology, Pl. Politechniki 1, 00-661 Warsaw, Poland D. B. Cline, B. Lisowski, C. Matthey, S. Otwinowski, Y. Seo, H. Wang, X. Yang Japan_Dec 2010 Slide# : 6 Department of Physics and Astronomy, University of California, Los Angeles, USA
ICARUS (CNGS2): the first large scale LAr experiment ● ICARUS represents a major milestone in the practical realization of a large scale LAr detector. Successfully operated on surface in Pavia in 2002, it is now operational in the underground HallB of LNGS. ● The T600 at LNGS will collect simultaneously “bubble chamber like” neutrino events events of different nature ● Cosmic ray events ≈ 80 ev/year of unbiased atmospheric CC neutrinos. Solar neutrino electron rates >5 MeV. Supernovae neutrinos. A zero background proton decay with 3 x 10 32 nucleons for ”exotic” channels. ● CERN beam associated events: 1200 ν µ CC ev/y and 7-8 ν e CC ev/year Observation of neu-tau events in the electron channel (with sensitivity comparable to the one of OPERA. A search for sterile neutrinos. ● After CNGS2 runs during 2011 and 2012, the “next step” for the T600 is a comprehensive search of sterile ν and anti- ν at the CERN PS. Japan_Dec 2010 Japan_Dec 2010 Slide# : 7 Slide# : 7
ν− e balanced events or ν− tau decays ? + LSND like sterile neutrinos τ -> e νν νν decays Likelihood distributions may separate an hypothetical LSND excess from the expected presence of τ − > ενν decays Likelihood weight
ICARUS T600 in LNGS Hall B 30 m 3 LAr Vessel 30 m 3 LN 2 Vessel N 2 Phase separator N 2 liquefiers: 10 units, 40 kW cryo-power Japan_Dec 2010 Japan_Dec 2010 Slide# : 9 Slide# : 9
T600 cryostats layout Pipe from safety magnetic disks Passive heaters Electronics (54000 channels) LN 2 Pumps LAr GAr purification purification systems systems Japan_Dec 2010 Japan_Dec 2010 Slide# : 10 Slide# : 10
Item Description Item Description 12 Evacuation piping 1 Drift ultra-pure LAr Volume (300 ton) 13 Racks for electronic readout 2 HV cathode (150 kV) 14 Gas recirculation & purification 3 Wire chamber readout planes (3) 15 Supporting feet 4 Drift field shaping rings 16 Protective gridding 5 Light collecting PM’s 17 Nitrogen cooling circuits 18 Liquid Nitrogen storage 6 HV feed through (150 kV) 19 External supporting structure 7 Aluminium Honeycomb container box 20 Main basement 8 Evacuated volume (cold) 21 Nitrogen re-liquefaction system 9 Supporting and insulating feet 22 Cryogenic plant 10 Thermal insulation and containment 23 Liquid transfer pump 11 Chimneys for readout electronics 24 Oxysorb/Hydrosorb filter in liquid phase Japan_Dec 2010 Slide# : 11
ICARUS front-end Electronics Multi-event H.V. (<±500 V) VME board (18/crate) circular buffer Liquid argon Gas (8x1ms) F F Sense wires A A (4-9m, 20pF/m) D D 4 Multiplexers (400ns x 8ch.) C C Twisted pair cables 10bit FADC Continuous Front-end (~5m, 50pF/m) 400ns sampling waveform Decoupling amplifiers 1mV/ADC Recording Boards (32/board); (~1000e-/ADC (32 ch.) 1500 e.n.c matches el. Noise) To storage 100 UHV feed-throughs: 576 channels (18 connectors x 32 + HV wire biasing) New Design based on multi-layer PCB with blind holes: electrical continuity ultra high vacuum tightness Japan_Dec 2010 Japan_Dec 2010 Slide# : 12 Slide# : 12
Thirty years of progress........ LAr is a cheap liquid LAr is a cheap liquid ( ≈ 1CHF/litre), vastly ( ≈ 1CHF/litre), vastly Magnetic field replaced by high produced by industry Bubble diameter ≈ 3 mm produced by industry accuracy 3D calorimetry. (diffraction limited) Gargamelle bubble chamber ICARUS electronic chamber “Bubble” size 3 x 3 x 0.3 mm 3 32 bar pressure no over-pressure 32 bar pressure no over-pressure Pulsed ≈ 1ms Continuously sensitive Pulsed ≈ 1ms Continuously sensitive Medium Heavy freon Medium Liquid Argon Presently T600 Sensitive mass 3.0 ton Sensitive mass Many ktons with > 600 ton Density 1.5 g/cm3 Density 1.4 g/cm3 of LAr, running Radiation length 11.0 cm Radiation length 14.0 cm underground Collision length 49.5 cm Collision length 54.8 cm at the LNGS dE/dx 2.3 MeV/cm dE/dx 2.1 MeV/cm Japan_Dec 2010 Japan_Dec 2010 Slide# : 13 Slide# : 13
Summary of LAr TPC performances ● Tracking device Precise event topology µ Momentum via multiple scattering e ● Measurement of local energy deposition dE/dx T300 real event e / γ separation (2%X 0 sampling) Particle ID by means of dE/dx vs range ● Total energy reconstruction of the events from charge integration Full sampling, homogeneous calorimeter with excellent accuracy for contained events RESOLUTIONS Low energy electrons: σ (E)/E = 11% / √ E(MeV)+2% Electromagn. showers: σ (E)/E = 3% / √ E(GeV) dE/dx distribution Hadron shower (pure LAr): σ (E)/E ≈ 30% / √ E(GeV) along a single muon track Japan_Dec 2010 Japan_Dec 2010 Slide# : 14 Slide# : 14
Muon momentum resolution by multiple scattering ● Muon momentum resolution Δ p/p=15% (A) from multiple scattering [Kalman filter] has been measured for E < 0.5 GeV. ● The procedure, validated on stopping muons, has been extended to higher energy with MC calculations; the resolution Δ p/p can be as good as 10%, depending mainly on track length (B) Japan_Dec 2010 Japan_Dec 2010 Slide# : 15 Slide# : 15
Electrons from muon decay ● Excellent resolution obtained from the measured decay electron spectrum (Michel parameter) from muon decays Precision calorimetry Japan_Dec 2010 Japan_Dec 2010 Slide# : 16 Slide# : 16
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