André Rubbia, ETH ZürichAndré Rubbia, ETH Zürich

January, 2004

The ICARUS project

André Rubbia - January 2004 3

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, CIEMATRUSSIA: INR (Moscow)

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, CIEMATRUSSIA: INR (Moscow)

André Rubbia - January 2004 4

The ICARUS project

Based on the Based on the liquid Argon time projection chamber technologyliquid Argon time projection chamber technology (originally developed at CERN and supported by the Italian Institute for (originally developed at CERN and supported by the Italian Institute for Nuclear Research (INFN) over many years of R&D)Nuclear Research (INFN) over many years of R&D)

Now a mature technology to detect with unprecedented quality the Now a mature technology to detect with unprecedented quality the trajectories of elementary particlestrajectories of elementary particles

Biggest achievement: Biggest achievement:

Construction of a fully instrumented 600 ton liquid argon experiment and operation on surface

Plan: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 5

Run 960, Event 4 Collection Left

25 cm

85 cm

Cosmic ray interactions with ICARUS 600 ton

176

cm

434 cm

Run 308, Event 160 Collection Left

265 cm

142 cm

Muon decay

Shower

Hadronic interaction

A 100 kton liquid argon underground

observatory for neutrino physics

and test of matter stability

Astrophysical neutrinos

Atmospheric

E ≈ 1 GeV

SolarE ≈ 10 MeV

Supernova

E ≈ 30 MeV

Artificial neutrinos

PS

Decay

Ring

SPS

-beams

Superbeams

€

π± → μ±μ

(− )

€

μ− → e−ν eν μ

μ + → e+νeν μ

⎫ ⎬ ⎪

⎭ ⎪

€

ZA→Z m1A β ± ν e

(− )

Select focusing Select focusing signsign

Select ionSelect ion

Select ring signSelect ring sign

Matter stability

100 kton = 6x1034 nucleons

Do they live “forever” ?

Concept: 100 kton liquid Argon detector

Insulation

≈70 m

h =20 m

Electronic crates

Open detector

Liquid ArgonD

rift

Gas Argon

Summary parameters liquid Argon 100 kton

DewarDewar≈≈70 m, height ≈ 20 m, passive perlite insulated, heat 70 m, height ≈ 20 m, passive perlite insulated, heat input ≈5W/minput ≈5W/m22

Argon storageArgon storage Boiling argon, low pressure (<100 mbar overpressure)Boiling argon, low pressure (<100 mbar overpressure)

Argon total volumeArgon total volume 73118 m73118 m33 (height = 19 m), ratio area/volume≈15% (height = 19 m), ratio area/volume≈15%

Argon total massArgon total mass 102365 tons102365 tons

Hydrostatic pressure at bottomHydrostatic pressure at bottom ≈≈3 atm3 atm

Inner detector dimensionsInner detector dimensions Disc Disc ≈70 m located in gas phase above liquid phase ≈70 m located in gas phase above liquid phase

Electron drift in liquidElectron drift in liquid20 m maximum drift, HV=2 MV for 20 m maximum drift, HV=2 MV for EE=1KV/cm, =1KV/cm, vvdd≈2 mm/µs, max drift time ≈10 ms≈2 mm/µs, max drift time ≈10 ms

Charge readout viewCharge readout view2 independent perpendicular views, 3mm pitch, in gas 2 independent perpendicular views, 3mm pitch, in gas phase (electron extraction) with charge amplification (typ. phase (electron extraction) with charge amplification (typ. x100)x100)

Charge readout channelsCharge readout channels ≈≈100000100000

Readout electronicsReadout electronics 100 “ICARUS-like” racks on top of dewar (1000 channels 100 “ICARUS-like” racks on top of dewar (1000 channels per crate)per crate)

Scintillation light readout Scintillation light readout Yes (also for triggering), 1000 immersed 8“ PMT with WLS Yes (also for triggering), 1000 immersed 8“ PMT with WLS (TPB)(TPB)

Visible light readoutVisible light readout Yes (Cerenkov light), 27000 immersed 8“ PMTs or 20% Yes (Cerenkov light), 27000 immersed 8“ PMTs or 20% coverage, single photon counting capabilitycoverage, single photon counting capability

André Rubbia - January 2004 13

Detector schematic layout

LAr

Cathode (–2MV)

E-f

ield

Extraction grid

Charge readout plane

GAr

UV & visible light readout PMT + race track

(Not to scale)

E≈ 1 kV/cm

E ≈ 3 kV/cm

Electronic racks

The “dedicated” cryogenic complex

External complex

Heatexchanger

Joule-Thompsonexpansion valve

W

Q

Argonpurification

Air

Hot GAr

Electricity

Underground complexGAr

LAr

LN2, …

Concept: Cryogenic parameters

Liquid Argon 1st filling timeLiquid Argon 1st filling time 2 years (assumed)2 years (assumed)

Liquid Argon 1st filling rateLiquid Argon 1st filling rate 1,2 liters/second or 150 tons/day1,2 liters/second or 150 tons/day

Liquid Argon refilling rateLiquid Argon refilling rate ≈≈0.3 liters/second0.3 liters/second or 23000 liters/day or 23000 liters/day

Purity of liquid ArgonPurity of liquid Argon

Required level of purityRequired level of purity < 0,1 ppb of O< 0,1 ppb of O22-equivalent-equivalent

Purification methodPurification methodContinuous recirculation through Continuous recirculation through commercially available “Oxysorb” commercially available “Oxysorb” cartridgescartridges

Gas & Liquid phase purificationGas & Liquid phase purification

Wished liquid recirculation timeWished liquid recirculation time ≈≈3 months3 months

Wished gas recirculation timeWished gas recirculation time ≈≈7 days7 days

Number of purification unitsNumber of purification units 30 (15+15)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