June 24, 2016
No writer credit found
Images credit: http://www3.imperial.ac.uk/newseventsimages?p_image_type=mainnews2012&p_image_id=18164
Artist’s rendering of the KM3NeT array. Credit: Marco Kraan/Property KM3NeT Consortium
KM3NeT – a European collaboration pioneering the deployment of kilometre cubed arrays of neutrino detectors off the Mediterranean coast – has reported in detail on the scientific aims, technology and costs of its proposal in the Journal of Physics G: Nuclear and Particle Physics.
Neutrinos are ideal messengers from the cosmos. These stable, sub-atomic particles can travel long distances without being disturbed by matter or magnetic fields in their path. Their detection is prized by astronomers as neutrino-emitting sources such as the remnants of Super Nova explosions provide important clues to the evolution of our universe. The study of neutrinos could also help in expanding our knowledge of atomic physics. However, there is a catch.
“The weak interaction between neutrinos and normal matter is a blessing and curse,” commented Maarten de Jong, who has been involved in the KM3NeT project since the first design study in 2006 and is spokesperson for the collaboration. “It makes detecting them notoriously difficult, which is why you need a giant detector.”
It’s a big undertaking. To detect neutrinos from the cosmos you need a massive site, which can then be used as a converter target as follows –
Firstly, a neutrino interacts with an atomic nucleus in the target medium to produce relativistic charged particles. Secondly, the passage of these relativistic charged particles through the medium produces so-called Cherenkov light (the typical blue light on pictures of nuclear reactors). And lastly, the Cherenkov light is detected by a 3-dimensional spatial array of incredibly sensitive photo-sensors.
Fortunately, Mother Earth is able to lend a helping hand in bringing down the cost of developing such a huge structure. “It turns out that the deep waters in the Mediterranean are ideal,” explained de Jong. “These natural waters come for free, are very transparent to the Cherenkov light, and sufficiently accessible to allow the deployment of strings of photo-sensors.”
At a depth of several kilometres there is no more daylight, which means that KM3NeT’s optical modules can be placed in darkness for maximum sensitivity to the neutrino-signalling Cherenkov light. Also, under these conditions the neutrino telescope can be operated 24 hours a day, 7 days a week.
The KM3NeT collaboration has developed what it believes is a cost-effective plan for building out this research infrastructure at the bottom of the sea. The phased rolled-out will consist of three so-called building blocks, where each building block comprises 115 strings of 18 optical modules (glass spheres containing 31 outward-facing photomultiplier tubes).
The strings, which can extend for several hundred metres, are anchored on the seabed and kept vertical by the buoyancy of the optical modules and the use of an additional buoy at the very top. These long chains of detectors are important, because they allow the scientists to reconstruct the trajectory of the incoming neutrinos. This data can then be used by researchers to identify the locations of the corresponding sources in outer space.
The array will provide a large piece of the puzzle required to monitor the whole of the sky for incoming neutrinos, linking existing telescopes based under the South Pole (IceCube) and in Lake Baikal, Russia (Gigaton Volume Detector – GVD).
U Wisconsin ICECUBE neutrino detector at the South Pole
GVD – no images made available
In December 2015, the KM3NeT collaboration successful tested the deployment of a string of its latest optical modules. It has already raised EURO 31 million to begin phase one of the project. The work builds on experience gained through ANTARES (a 12 string array based off the coast of France).
More information: Journal of Physics G: Nuclear and Particle Physics. DOI: 10.1088/0954-3899/43/8/084001
Map of the various preparation, integration and installation sites at the time of this writing. (24 June 2016)
S Adrián-Martínez1, M Ageron2, F Aharonian3, S Aiello4, A Albert5, F Ameli6, E Anassontzis7, M Andre8, G Androulakis9, M Anghinolfi10, G Anton11, M Ardid1, T Avgitas12, G Barbarino13,14, E Barbarito15, B Baret12, J Barrios-Martí16, B Belhorma17, A Belias9, E Berbee18, A van den Berg19, V Bertin2, S Beurthey2, V van Beveren18, N Beverini20,21, S Biagi22, A Biagioni6, M Billault2, M Bondì4, R Bormuth18,23, B Bouhadef21, G Bourlis24, S Bourret12, C Boutonnet12, M Bouwhuis18, C Bozza25, R Bruijn26, J Brunner2, E Buis27, J Busto2, G Cacopardo22, L Caillat2, M Calamai21, D Calvo16, A Capone6,28, L Caramete29, S Cecchini30, S Celli6,28,31, C Champion12, R Cherkaoui El Moursli32, S Cherubini22,33, T Chiarusi30, M Circella15, L Classen11, R Cocimano22, J A B Coelho12, A Coleiro12, S Colonges12, R Coniglione22, M Cordelli34, A Cosquer2, P Coyle2, A Creusot12, G Cuttone22, A D’Amico18, G De Bonis6, G De Rosa13,14, C De Sio25, F Di Capua13, I Di Palma6,28, A F Díaz García35, C Distefano22, C Donzaud12, D Dornic2, Q Dorosti-Hasankiadeh19, E Drakopoulou9, D Drouhin5, L Drury3, M Durocher22,31, T Eberl11, S Eichie11,36, D van Eijk18, I El Bojaddaini37, N El Khayati32, D Elsaesser38, A Enzenhöfer2, F Fassi32, P Favali39, P Fermani6, G Ferrara22,33, C Filippidis9, G Frascadore22, L A Fusco30,40, T Gal11, S Galatà12, F Garufi13,14, P Gay12,41, M Gebyehu18, V Giordano4, N Gizani24, R Gracia12, K Graf11, T Grégoire12, G Grella25, R Habel34, S Hallmann11, H van Haren42, S Harissopulos9, T Heid11, A Heijboer18, E Heine18, S Henry2, J J Hernández-Rey16, M Hevinga19, J Hofestädt11, C M F Hugon10, G Illuminati16, C W James11, P Jansweijer18, M Jongen18, M de Jong18, M Kadler38, O Kalekin11, A Kappes11, U F Katz11, P Keller2, G Kieft18, D Kießling11, E N Koffeman18, P Kooijman26,43, A Kouchner12, V Kulikovskiy22, R Lahmann11, P Lamare2, A Leisos24, E Leonora4, M Lindsey Clark12, A Liolios44, C D Llorens Alvarez1, D Lo Presti4, H Löhner19, A Lonardo6, M Lotze16, S Loucatos12, E Maccioni20,21, K Mannheim38, A Margiotta30,40, A Marinelli20,21, O Mariş29, C Markou9, J A Martínez-Mora1, A Martini34, R Mele13,14, K W Melis18, T Michael18, P Migliozzi13, E Migneco22, P Mijakowski45, A Miraglia22, C M Mollo13, M Mongelli15, M Morganti21,46, A Moussa37, P Musico10, M Musumeci22, S Navas35, C A Nicolau6, I Olcina16, C Olivetto12, A Orlando22, A Papaikonomou24, R Papaleo22, G E Păvălaş29, H Peek18, C Pellegrino30,40, C Perrina6,28, M Pfutzner18, P Piattelli22, K Pikounis9, G E Poma22,33, V Popa29, T Pradier47, F Pratolongo10, G Pühlhofer48, S Pulvirenti22, L Quinn2, C Racca5, F Raffaelli21, N Randazzo4, P Rapidis9, P Razis49, D Real16, L Resvanis7, J Reubelt11, G Riccobene22, C Rossi10, A Rovelli22, M Saldaña1, I Salvadori2, D F E Samtleben18,23, A Sánchez García16, A Sánchez Losa15, M Sanguineti10, A Santangelo48, D Santonocito22, P Sapienza22, F Schimmel18, J Schmelling18, V Sciacca22, M Sedita22, T Seitz11, I Sgura15, F Simeone6, I Siotis9, V Sipala4, B Spisso13, M Spurio30,40, G Stavropoulos9, J Steijger18, S M Stellacci25, D Stransky11, M Taiuti10,50, Y Tayalati37,32, D Tézier2, S Theraube2, L Thompson51, P Timmer18, C Tönnis16, L Trasatti34, A Trovato22, A Tsirigotis24, S Tzamarias24, E Tzamariudaki9, B Vallage12, V Van Elewyck12, J Vermeulen18, P Vicini6, S Viola22, D Vivolo13,14, M Volkert11, G Voulgaris7, L Wiggers18, J Wilms36, E de Wolf18,26, K Zachariadou52, J D Zornoza16 and J Zúñiga16
1 Universitat Politècnica de València, Instituto de Investigación para la Gestión Integrada de las Zonas Costeras, C/ Paranimf, 1, Gandia, E-46730, Spain
2 Aix-Marseille Université, CNRS/IN2P3, CPPM UMR 7346, F-13288, Marseille, France
3 The Dublin Institute for Advanced Studies, 10 Burlington Road, Dublin 4, Ireland
4 INFN, Sezione di Catania, Via Santa Sofia 64, Catania, I-95123, Italy
5 Université de Strasbourg, Université de Haute Alsace, GRPHE, 34, Rue du Grillenbreit, Colmar, F-68008, France
6 INFN, Sezione di Roma, Piazzale Aldo Moro 2, Roma, I-00185, Italy
7 Physics Department, N. and K. University of Athens, Athens, Greece
8 Universitat Politècnica de Catalunya, Laboratori d’Aplicacions Bioacústiques, Centre Tecnològic de Vilanova i la Geltrú, Avda. Rambla Exposició, s/n, Vilanova i la Geltrú, E-08800, Spain
9 NCSR Demokritos, Institute of Nuclear and Particle Physics, Ag. Paraskevi Attikis, Athens, 15310, Greece
10 INFN, Sezione di Genova, Via Dodecaneso 33, Genova, I-16146, Italy
11 Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Straße 1, D-91058 Erlangen, Germany
12 APC, Université Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, F-75205 Paris, France
13 INFN, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Via Cintia ed. G, Napoli, I-80126, Italy
14 University of Napoli, Dip. Scienze fisiche, Complesso Universitario di Monte S. Angelo, Via Cintia ed. G, Napoli, I-80126, Italy
15 INFN, Sezione di Bari, Via Amendola 173, Bari, I-70126, Italy
16 IFIC—Instituto de Física Corpuscular (CSIC—Universitat de València), c/Catedrático José Beltrán, 2, E-46980 Paterna, Valencia, Spain
17 National Center for Energy Sciences and Nuclear Techniques, B.P. 1382, R.P. 10001 Rabat, Morocco
18 FOM, Nikhef, PO Box 41882, Amsterdam, 1098 DB, The Netherlands
19 KVI-CART University of Groningen, Groningen, The Netherlands
20 Università di Pisa, Dipartimento di Fisica, Largo Bruno Pontecorvo 3, Pisa, I-56127, Italy
21 INFN, Sezione di Pisa, Largo Bruno Pontecorvo 3, Pisa, I-56127, Italy
22 INFN, Laboratori Nazionali del Sud, Via S. Sofia 62, Catania, I-95123, Italy
23 Leiden University, Leiden Institute of Physics, PO Box 9504, Leiden, 2300 RA, The Netherlands
24 Hellenic Open University, School of Science / Technology, Natural Sciences, Sahtouri St. / Ag. Andreou St. 16, Patra, 26222, Greece
25 University of Salerno, Department of Physics, Via Giovanni Paolo II 132, Fisciano, I-84084, Italy
26 University of Amsterdam, Institute of Physics/IHEF, PO Box 94216, Amsterdam, 1090 GE, The Netherlands
27 TNO, Technical Sciences, PO Box 155, Delft, 2600 AD, The Netherlands
28 Università La Sapienza, Dipartimento di Fisica, Piazzale Aldo Moro 2, Roma, I-00185, Italy
29 ISS, 242, Vacaresti, Bucharest, 40061, Romania
30 INFN, Sezione di Bologna, v.le C. Berti-Pichat, 6/2, Bologna, I-40127, Italy
31 Gran Sasso Science Institute, GSSI, Viale Francesco Crispi 7, L’Aquila, I-67100, Italy
32 University Mohammed V in Rabat, Faculty of Sciences, 4 av. Ibn Battouta, B.P. 1014, R.P. 10000 Rabat, Morocco
33 University of Catania, Dipartimento di Fisica ed Astronomia di Catania, Via Santa Sofia 64, Catania, I-95123, Italy
34 INFN, LNF, Via Enrico Fermi , 40, Frascati, I-00044, Italy
35 Universidad de Granada & C.A.F.P.E, Av. del Hospicio s/n, E-18071 Granada, Spain
36 Friedrich-Alexander-Universität Erlangen-Nürnberg, Remeis Sternwarte, Sternwartstraße 7, D-96049 Bamberg, Germany
37 University Mohammed I, Faculty of Sciences, BV Mohammed VI, B.P. 717, R.P. 60000 Oujda, Morocco
38 University Würzburg, Emil-Fischer-Straße 31, D-97074 Würzburg, Germany
39 INGV, Via di Vigna Murata, 605, Rome, I-00143, Italy
40 University of Bologna, Dipartimento di Fisica e Astronomia, v.le C. Berti-Pichat, 6/2, Bologna, I-40127, Italy
41 IN2P3, LPC, Campus des Cézeaux 24, avenue des Landais BP 80026, Aubière Cedex, F-63171, France
42 NIOZ, PO Box 59, Den Burg, Texel, 1790 AB, The Netherlands
43 Utrecht University, Department of Physics and Astronomy, PO Box 80000, Utrecht, 3508 TA, The Netherlands
44 Aristotle University Thessaloniki, University Campus, Thessaloniki, 54124, Greece
45 National Centre for Nuclear Research, 00-681 Warsaw, Poland
46 Accademia Navale di Livorno, Viale Italia 72, Livorno, I-57100, Italy
47 IN2P3, IPHC, 23 rue du Loess, Strasbourg, F-67037, France
48 Eberhard Karls Universität Tübingen, Institut für Astronomie und Astrophysik, Sand 1, D-72076 Tübingen, Germany
49 University of Cyprus, Physics, Kallipoleos 75, Nicosia, 1678, Cyprus
50 University of Genova, Via Dodecaneso 33, Genova, I-16146, Italy
51 University of Sheffield, Department of Physics and Astronomy, Hounsfield Road, Sheffield, S3 7RH, UK
52 Technological Education Institute of Pireaus, Thivon and P. Ralli Str. 250, Egaleo—Athens, 12244, Greece
See the full article here .
Please help promote STEM in your local schools.
Stem Education Coalition
About Phys.org in 100 Words
Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.