Presentation of background leading to the

André Rubbia, ETH Zürich
January, 2004
The ICARUS project
The ICARUS collaboration (25 institutes, ≈150 physicists)
M. Aguilar-Benitez, S. Amoruso, Yu. Andreew, P. Aprili, F. Arneodo, B. Babussinov, B. Badelek, A. Badertscher, M.
Baldo-Ceolin, G. Battistoni, B. Bekman, P. Benetti, E. Bernardini, A. Borio di Tigliole, M. Bischofberger, R. Brunetti, R.
Bruzzese, A. Bueno, C. Burgos, E. Calligarich, D. Cavalli, F. Cavanna, F. Carbonara, P. Cennini, S. Centro, M.
Cerrada, A. Cesana, R. Chandrasekharan, C. Chen, D. B. Chen, Y. Chen, R. Cid, D. Cline, P. Crivelli, A.G. Cocco, A.
Dabrowska, Z. Dai, M. Daniel, M. Daszkiewicz, C. De Vecchi, A. Di Cicco, R. Dolfini, A. Ereditato, M. Felcini, A. Ferrari,
F. Ferri, G. Fiorillo, M.C. Fouz, S. Galli, D. Garcia, Y. Ge, D. Gibin, A. Gigli Berzolari, I. Gil-Botella, S.N. Gninenko, N.
Goloubev, A. Guglielmi, K. Graczyk, L. Grandi, K. He, J. Holeczek, X. Huang, C. Juszczak, D. Kielczewska, M.
Kirsanov, J. Kisiel, L. Knecht, T. Kozlowski, H. Kuna-Ciskal, N. Krasnikov, P. Ladron de Guevara, M. Laffranchi, J.
Lagoda, Z. Li, B. Lisowski, F. Lu, J. Ma, N. Makrouchina, G. Mangano, G. Mannocchi, M. Markiewicz, A. Martinez de la
Osa, V. Matveev, C. Matthey, F. Mauri, D. Mazza, A. Melgarejo, G. Meng, A. Meregaglia, M. Messina, C. Montanari, S.
Muraro, G. Natterer, S. Navas-Concha, M. Nicoletto, G. Nurzia, C. Osuna, 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, L. Romero, E. Rondio, M. Rossella, A. Rubbia, C. Rubbia, P. Sala, N. Santorelli, D. Scannicchio, E.
Segreto, Y. Seo, F. Sergiampietri, J. Sobczyk, N. Spinelli, J. Stepaniak, M. Stodulski, M. Szarska, M. Szeptycka, M.
Szeleper, M. Terrani, R. Velotta, S. Ventura, C. Vignoli, H. Wang, X. Wang, C. Willmott, M. Wojcik, J. Woo, G. Xu, Z.
Xu, X. Yang, A. Zalewska, J. Zalipska, C. Zhang, Q. Zhang, S. Zhen, W. Zipper.
ITALY: L'Aquila, LNF, LNGS, Milano, Napoli, Padova, Pavia, Pisa, CNR Torino, Torino Univ., Politec. Milano.
SWITZERLAND: ETH/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, CIEMAT
RUSSIA: INR (Moscow)
André Rubbia - January 2004
3
The ICARUS project



Based on the liquid Argon time projection chamber technology (originally
developed at CERN and supported by the Italian Institute for Nuclear
Research (INFN) over many years of R&D)
Now a mature technology to detect with unprecedented quality the
trajectories of elementary particles
Biggest achievement:
 Construction of a fully instrumented 600 ton liquid argon experiment and
operation on surface

Plan:
 To install and operate a 3000 tons of liquid argon experiment underground at
the LNGS (National Laboratory of Gran Sasso) near Rome, Italy
André Rubbia - January 2004
4
Cosmic ray interactions with ICARUS 600 ton
Shower
176 cm
25 cm
434 cm
85 cm
265 cm
142 cm
Muon decay
Run 960, Event 4 Collection Left
André Rubbia - January 2004
Hadronic interaction
Run 308, Event 160 Collection Left
5
A 100 kton liquid
argon underground
observatory for
neutrino physics and
test of matter stability
Astrophysical
neutrinos
Atmosphe
ric
Solar
En ≈ 10 MeV
Supernov
a
Artificial neutrinos

 
Superbeams

Select focusing
n sign
( )
b-beams
Z
Decay
Ring
SPS
PS
  e nen  

Select ring sign



  e nen 



A A b
Select ion
Z 1

( )
ne
Matter stability
34
6x10
100 kton =
nucleons
Do they live “forever” ?
Concept: 100 kton liquid Argon detector
Electronic crates
f≈70 m
h =20 m
Insulation
Open detector
Drift
Gas Argon
Liquid Argon
Summary parameters liquid Argon 100 kton
Dewar
f≈70
m, height ≈ 20 m, passive perlite insulated, heat
input ≈5W/m2
Argon storage
Boiling argon, low pressure (<100 mbar overpressure)
Argon total volume
73118 m3 (height = 19 m), ratio area/volume≈15%
Argon total mass
102365 tons
Hydrostatic pressure at bottom
≈3 atm
Inner detector dimensions
Disc f ≈70 m located in gas phase above liquid phase
Electron drift in liquid
20 m maximum drift, HV=2 MV for E=1KV/cm,
vd≈2 mm/µs, max drift time ≈10 ms
Charge readout view
2 independent perpendicular views, 3mm pitch, in gas
phase (electron extraction) with charge amplification (typ.
x100)
Charge readout channels
≈100000
Readout electronics
100 “ICARUS-like” racks on top of dewar (1000 channels
per crate)
Scintillation light readout
Yes (also for triggering), 1000 immersed 8“ PMT with WLS
(TPB)
Visible light readout
Yes (Cerenkov light), 27000 immersed 8“ PMTs or 20%
coverage, single photon counting capability
Detector schematic layout
Charge
readout
plane
GAr
E ≈ 3 kV/cm
E-field
Extraction
grid
Electronic
racks
LAr
E≈ 1 kV/cm
UV &
visible
light
readout
PMT +
race track
Cathode (–2MV)
André Rubbia - January 2004
(Not to scale)
13
The “dedicated” cryogenic complex
Electricity
Air
Hot GAr
W
Underground
complex
GAr
LAr
Joule-Thompson
expansion valve
Q
Heat
exchanger
External complex
Argon
purification
LN2, …
Concept: Cryogenic parameters
Liquid Argon 1st filling time
2 years (assumed)
Liquid Argon 1st filling rate
1,2 liters/second or 150 tons/day
Liquid Argon refilling rate
≈0.3 liters/second or 23000 liters/day
Purity of liquid Argon
Required level of purity
< 0,1 ppb of O2-equivalent
Purification method
Continuous recirculation through
commercially available “Oxysorb”
cartridges
Gas & Liquid phase purification
Wished liquid recirculation time
≈3 months
Wished gas recirculation time
≈7 days
Number of purification units
30 (15+15)
Wish-list for this study
Feasibility: storage tank
•Underground storage of large quantity of
liquid Argon at cryogenic temperature
•Vacuum technology (external impurity
tightness)
•“Clean” internal materials (e.g. SS, surface
treated)
•Radiopurity of materials employed
Undergound construction
strategy
•Tunnel access
•E.g. Fréjus
•Mine access
•E.g. Polish site
•Problem of space logistics
•Safety
Operation
•LAr level constant (refilling)
•LAr purity (continuous recirculation)
•Emptying?
•Safety
Feasibility: Instrumentation
•Internal mechanics (our instrumentation)
•Internal-external UHV cold-hot interface
Feasibility: Financing & time
•Cost (order of magnitude)
•Construction timescale
Outlook
•Presentation of polish site
•W. Pytel
•Presentation of Fréjus site
•L. Mosca
•Discussion on how to proceed