The ICARUS T600 Liquid Argon
Time Projection Chamber
Francesco Arneodo
Laboratori Nazionali del Gran Sasso
on behalf of the ICARUS Collaboration
F. Arneodo Imaging 2003
The ICARUS Collaboration
S. Amoruso, P. Aprili, F. Arneodo, B. Babussinov, B. Badelek, A. Badertscher, M. Baldo-Ceolin, G. Battistoni,
B. Bekman, P. Benetti, A. Borio di Tigliole, M. Bischofberger, R. Brunetti, R. Bruzzese, A. Bueno, E. Calligarich,
D. Cavalli, F. Cavanna, F. Carbonara, P. Cennini, S. Centro, A. Cesana, C. Chen, Y. Chen, D. Cline, P. Crivelli,
A.G. Cocco, A. Dabrowska, Z. Dai, M. Daszkiewicz, A. Di Cicco, R. Dolfini, A. Ereditato, M. Felcini, A. Ferrari, F.
Ferri, G. Fiorillo, S. Galli, Y. Ge, D. Gibin, A. Gigli Berzolari, I. Gil-Botella, A. Guglielmi, K. Graczyk,
L.
Grandi, X. He, J. Holeczek, C. Juszczak, D. Kielczewska, J. Kisiel, L. Knecht, T. Kozlowski, H. Kuna-Ciskal, M.
Laffranchi, J. Lagoda, B. Lisowski, F. Lu, G. Mangano, G. Mannocchi, M. Markiewicz, F. Mauri, C. Matthey, G.
Meng, M. Messina, C. Montanari, S. Muraro, G. Natterer, S. Navas-Concha, M. Nicoletto, S. Otwinowski, Q.
Ouyang, O. Palamara, D. Pascoli, L. Periale, G. Piano Mortari, A. Piazzoli, P. Picchi, F. Pietropaolo,
W.
Polchlopek, T. Rancati, A. Rappoldi, G.L. Raselli, J. Rico, E. Rondio, M. Rossella, A. Rubbia, C. Rubbia, P.
Sala, R. Santorelli, D. Scannicchio, E. Segreto, Y. Seo, F. Sergiampietri, J. Sobczyk, N. Spinelli,
J.
Stepaniak, M. Stodulski, M. Szarska, M. Szeptycka, M. Terrani, R. Velotta, S. Ventura, C. Vignoli, H. Wang, X.
Wang, M. Wojcik, X. Yang, A. Zalewska, J. Zalipska, P. Zhao, W. Zipper.
ITALY: L'Aquila, LNF, LNGS, Milano, Napoli, Padova, Pavia, Pisa, CNR Torino, Politec. Milano.
SWITZERLAND: ETHZ Zürich.
CHINA: Academia Sinica Beijing.
POLAND: Univ. of Silesia Katowice, Univ. of Mining and Metallurgy Krakow, Inst. of Nucl. Phys.
Krakow, Jagellonian Univ. Krakow, Univ. of Technology Krakow, A.Soltan Inst. for Nucl. Studies
Warszawa, Warsaw Univ., Wroclaw Univ.
USA: UCLA Los Angeles.
SPAIN: Univ. of Granada.
F. Arneodo Imaging 2003
Outline
• The LAr TPC Technology
• The T600 Detector
• Results from the 2001 run in Pavia
F. Arneodo Imaging 2003
The technique - I
Operating principles of the ICARUS LAr TPC:
• ionizing events taking place in a
volume of LAr (where a uniform
electric field is applied) produce
electron-ion pairs
• These charges drift along the field
lines. The motion of the much faster
electrons induces a current on the
anode. The electrons can drift several
metres if the LAr is highl purified
(electronegative impurities < 0.1 ppb
O2 equiv.)
F. Arneodo Imaging 2003
The LAr TPC Technology (2)
Non-destructive multiple readout
Raw Data from a 10 m3 prototype
eIonizing track
Charge
Scintillation Light
2nd
Induction wire
grid (x view)
d
d
p
Charge
1st Induction
wire/screen grid
Signals induced
C
Time -drift
B Drift time
A
C
Collection wire
grid (y view)
A B
Drift time
400 ns sampling
Continuous
waveform
recording
F. Arneodo Imaging 2003
The LAr TPC Technology (3)
• No charge multiplication occurs in LAr
• LAr is also a very good scintillator scintillation light
(l = 128 nm) provides a prompt signal to be used for
triggering purposes and for absolute event time
measurement
•
•
High electron mobility (~500 cm2V-1s-1)
Possibility of extreme purification (<0.1 ppb O2)
• Long electron life time (>ms)
•
High electron-ion pairs yield
and drift paths (>m)
(~ 10000 e- for 2 mm of a m.i.p. track)
density: 1.4 g/cm3
dE/dx: 2 MeV/c
•
Available in large quantities
(GAr ~ 0.9% of air)
F. Arneodo Imaging 2003
The T600 Module
• Two separate containers
– inner volume/cont. =
3.6 x 3.9 x 19.6 m3
• Sensitive mass = 476 t
• 4 wire chambers with 3
readout planes at 0°, ±60°
(two chambers / container)
– ≈ 54000 wires (chann.)
• Maximum drift = 1.5 m
– HV = -75 kV @ 0.5 kV/cm
• Scintillation light readout
with 8” VUV sensitive PMTs
F. Arneodo Imaging 2003
The T600 Module during construction
LAr Cryostat (half-module)
4m
4m
20 m
F. Arneodo Imaging 2003
View of the inner detector
The T600 Module
• Approved and funded in 1996
• Built between years 1997 and 2001
• Completely assembled in the INFN
assembly hall in Pavia
• Demonstration test run during first
half 2001
– Three months duration
– Completely successful
– Data taking with cosmic rays
• Installation plan in the Gran Sasso
underground Lab completed early
2003
• Transportation and installation in
LNGS in 2003-2004
F. Arneodo Imaging 2003
Lifetime evolution during T600 Pavia run
F. Arneodo Imaging 2003
T600 Data
6m
Muon bundle event
(Run 699, Event 48)
F. Arneodo Imaging 2003
3-D reconstruction
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e.m + hadron shower
2.2 m
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Long longitudinal muon track crossing the cathode plane
1.5 m
Right Chamber
18 m
1.5 m
Left Chamber
Cathode
Track Length = 18.2 m
dE/dx = 2.1 MeV/cm
3D View
Top View
3-D reconstruction of the long track
F. Arneodo Imaging 2003
dE/dx distribution along the track
3d reconstruction of a single muon
QuickTime™ and a
GIF decompressor
are needed to see this picture.
F. Arneodo Imaging 2003
Air Shower
run 834 ev. 6
right chamber collection view
left chamber collection view
F. Arneodo Imaging 2003
Stopping muon reconstruction example
 [AB]  e  [BC]
Run 939 Event 95 Right chamber
Induction 1 view
µ+
A
B
e+
Induction 2 view
C
A
µ+
B
e+
Collection view
C
F. Arneodo Imaging 2003
Te=36.2 MeV
Range=15.4 cm
d-rays

T600 Data
1.8 MeV
3.2 MeV
10 MeV
Two
consecutive
wires
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In-flight annihilation of positron
≈20% of positrons from µ decays expected to annihilate before stopping
Run 844, Event 24
e+e- pair


e+
+
Collection view
Induction 2 view
annihilation point
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Physics goals
• atmospheric and long baseline n studies
• proton decay
F. Arneodo Imaging 2003
Work is going on:
• Installation at Gran Sasso: tenders,
infrastructures, etc.
• Optimization of electronics and trigger
• Analysis (calorimetry,  momentum with
multiple scattering, muon bundles,
scintillation and Cherenkov light)
F. Arneodo Imaging 2003