@article{3064385,
    title = "Expansion cone for the 3-inch PMTs of the KM3NeT optical modules",
    author = "Adrian-Martinez, S. and Ageron, M. and Aguilar, J.A. and Aharonian, F. and Aiello, S. and Albert, A. and Alexandri, M. and Ameli, M. and Anassontzis, E.G. and Anghinolfi, M. and Anton, G. and Anvar, S. and Ardid, M. and Assis Jesus, A. and Aubert, J.-J. and Bakker, R. and Ball, A.E. and Barbarino, G. and Barbarito, E. and Barbato, F. and Baret, B. and De Bel, M. and Belias, A. and Bellou, N. and Berbee, E. and Berkien, A. and Bersani, A. and Bertin, V. and Beurthey, S. and Biagi, S. and Bigongiari, C. and Bigourdan, B. and Billault, M. and De Boer, R. and Boer Rookhuizen, H. and Bonori, M. and Borghini, M. and Bou-Cabo, M. and Bouhadef, B. and Bourlis, G. and Bouwhuis, M. and Bradbury, S. and Brown, A. and Bruni, F. and Brunner, J. and Brunoldi, M. and Busto, J. and Cacopardo, G. and Caillat, L. and Calvo Díaz-Aldagalán, D. and Calzas, A. and Canals, M. and Capone, A. and Carr, J. and Castorina, E. and Cecchini, S. and Ceres, A. and Cereseto, R. and Chaleil, Th. and Chateau, F. and Chiarusi, T. and Choqueuse, D. and Christopoulou, P.E. and Chronis, G. and Ciaffoni, O. and Circella, M. and Cocimano, R. and Cohen, F. and Colijn, F. and Coniglione, R. and Cordelli, M. and Cosquer, A. and Costa, M. and Coyle, P. and Craig, J. and Creusot, A. and Curtil, C. and D'Amico, A. and Damy, G. and De Asmundis, R. and De Bonis, G. and Decock, G. and Decowski, P. and Delagnes, E. and De Rosa, G. and Distefano, C. and Donzaud, C. and Dornic, D. and Dorosti-Hasankiadeh, Q. and Drogou, J. and Drouhin, D. and Druillole, F. and Drury, L. and Durand, D. and Durand, G.A. and Eberl, T. and Emanuele, U. and Enzenhöfer, A. and Ernenwein, J.-P. and Escoffier, S. and Espinosa, V. and Etiope, G. and Favali, P. and Felea, D. and Ferri, M. and Ferry, S. and Flaminio, V. and Folger, F. and Fotiou, A. and Fritsch, U. and Gajanana, D. and Garaguso, R. and Gasparini, G.P. and Gasparoni, F. and Gautard, V. and Gensolen, F. and Geyer, K. and Giacomelli, G. and Gialas, I. and Giordano, V. and Giraud, J. and Gizani, N. and Gleixner, A. and Gojak, C. and Gómez-González, J.P. and Graf, K. and Grasso, D. and Grimaldi, A. and Groenewegen, R. and Guédé, Z. and Guillard, G. and Guilloux, F. and Habel, R. and Hallewell, G. and Van Haren, H. and Van Heerwaarden, J. and Heijboer, A. and Heine, E. and Hernández-Rey, J.J. and Herold, B. and Van De Hoek, M. and Hogenbirk, J. and Hößl, J. and Hsu, C.C. and Imbesi, M. and Jamieson, A. and Jansweijer, P. and De Jong, M. and Jouvenot, F. and Kadler, M. and Kalantar-Nayestanaki, N. and Kalekin, O. and Kappes, A. and Karolak, M. and Katz, U.F. and Kavatsyuk, O. and Keller, P. and Kiskiras, Y. and Klein, R. and Kok, H. and Kontoyiannis, H. and Kooijman, P. and Koopstra, J. and Kopper, C. and Korporaal, A. and Koske, P. and Kouchner, A. and Koutsoukos, S. and Kreykenbohm, I. and Kulikovskiy, V. and Laan, M. and La Fratta, C. and Lagier, P. and Lahmann, R. and Lamare, P. and Larosa, G. and Lattuada, D. and Leisos, A. and Lenis, D. and Leonora, E. and Le Provost, H. and Lim, G. and Llorens, C.D. and Lloret, J. and Löhner, H. and Lo Presti, D. and Lotrus, P. and Louis, F. and Lucarelli, F. and Lykousis, V. and Malyshev, D. and Mangano, S. and Marcoulaki, E.C. and Margiotta, A. and Marinaro, G. and Marinelli, A. and Maris, O. and Markopoulos, E. and Markou, C. and Martínez-Mora, J.A. and Martini, A. and Marvaldi, J. and Masullo, R. and Maurin, G. and Migliozzi, P. and Migneco, E. and Minutoli, S. and Miraglia, A. and Mollo, C.M. and Mongelli, M. and Monmarthe, E. and Morganti, M. and Mos, S. and Motz, H. and Moudden, Y. and Mul, G. and Musico, P. and Musumeci, M. and Naumann, Ch. and Neff, M. and Nicolaou, C. and Orlando, A. and Palioselitis, D. and Papageorgiou, K. and Papaikonomou, A. and Papaleo, R. and Papazoglou, I.A. and Pǎvǎlas, G.E. and Peek, H.Z. and Perkin, J. and Piattelli, P. and Popa, V. and Pradier, T. and Presani, E. and Priede, I.G. and Psallidas, A. and Rabouille, C. and Racca, C. and Radu, A. and Randazzo, N. and Rapidis P.a. and Razis, P. and Real, D. and Reed, C. and Reito, S. and Resvanis, L.K. and Riccobene, G. and Richter, R. and Roensch, K. and Rolin, J. and Rose, J. and Roux, J. and Rovelli, A. and Russo, A. and Russo, G.V. and Salesa, F. and Samtleben, D. and Sapienza, P. and Schmelling, J.-W. and Schmid, J. and Schnabel, J. and Schroeder, K. and Schuller, J.-P. and Schussler, F. and Sciliberto, D. and Sedita, M. and Seitz, T. and Shanidze, R. and Simeone, F. and Siotis, I. and Sipala, V. and Sollima, C. and Sparnocchia, S. and Spies, A. and Spurio, M. and Staller, T. and Stavrakakis, S. and Stavropoulos, G. and Steijger, J. and Stolarczyk, Th. and Stransky, D. and Taiuti, M. and Taylor, A. and Thompson, L. and Timmer, P. and Tonoiu, D. and Toscano, S. and Touramanis, C. and Trasatti, L. and Traverso, P. and Trovato, A. and Tsirigotis, A. and Tzamarias, S. and Tzamariudaki, E. and Urbano, F. and Vallage, B. and Van Elewyck, V. and Vannoni, G. and Vecchi, M. and Vernin, P. and Viola, S. and Vivolo, D. and Wagner, S. and Werneke, P. and White, R.J. and Wijnker, G. and Wilms, J. and De Wolf, E. and Yepes, H. and Zhukov, V. and Zonca, E. and Zornoza, J.D. and Zúñiga, J.",
    journal = "Journal of Instrumentation",
    year = "2013",
    volume = "8",
    number = "3",
    issn = "1748-0221",
    doi = "10.1088/1748-0221/8/03/T03006",
    keywords = "Astroparticle physics;  Cherenkov Detectors;  Digital optical modules;  High energy neutrinos;  Neutrino interactions;  Optical detectors;  Photo multiplier tube (PMTs);  Photocathode sensitivity, Cerenkov counters;  Detectors;  Elementary particles;  Expansion;  Light;  Photocathodes, Particle detectors",
    abstract = "Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45° with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones.© 2013 IOP Publishing Ltd and Sissa Medialab srl."
}