Deep sea tests of a prototype of the KM3NeT digital optical module

The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deepwaters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same (40)Kdecay and the localisation of bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions

Detection potential of the KM3NeT detector for high-energy neutrinos from the Fermi bubbles

A recent analysis of the Fermi Large Area Telescope data provided evidence for a high-intensity emission of high-energy gamma rays with a E 2 spectrum from two large areas, spanning 50 above and below the Galactic centre (the ‘‘Fermi bubbles’’). A hadronic mechanism was proposed for this gamma-ray emission making the Fermi bubbles promising source candidates of high-energy neutrino emission. In this work Monte Carlo simulations regarding the detectability of high-energy neutrinos from the Fermi bubbles with the future multi-km3 neutrino telescope KM3NeT in the Mediterranean Sea are presented. Under the hypothesis that the gamma-ray emission is completely due to hadronic processes, the results indicate that neutrinos from the bubbles could be discovered in about one year of operation, for a neutrino spectrum with a cutoff at 100 TeV and a detector with about 6 km3 of instrumented volume. The effect of a possible lower cutoff is also considered.Published7–141.8. Osservazioni di geofisica ambientaleJCR Journalrestricte

Expansion cone for the 3-inch PMTs of the KM3NeT optical modules

[EN] 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 degrees 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.This work is supported through the EU, FP6 Contract no. 011937, FP7 grant agreement no. 212252, and the Dutch Ministry of Education, Culture and Science.Adrián Martínez, S.; Ageron, M.; Aguilar, JA.; Aharonian, F.; Aiello, S.; Albert, A.; Alexandri, M.... (2013). Expansion cone for the 3-inch PMTs of the KM3NeT optical modules. Journal of Instrumentation. 8(3):1-19. https://doi.org/10.1088/1748-0221/8/03/T03006S1198

Time-dependent cardiovascular treatment benefit model for lipid-lowering therapies.

Background With the availability of new lipid-lowering therapy options, there is a need to compare the expected clinical benefit of different treatment strategies in different patient populations and over various time frames. We aimed to develop a time-dependent model from published randomized controlled trials summarizing the relationship between low-density lipoprotein cholesterol lowering and cardiovascular risk reduction and to apply the model to investigate the effect of treatment scenarios over time. Methods and Results A cardiovascular treatment benefit model was specified with parameters as time since treatment initiation, magnitude of low-density lipoprotein cholesterol reduction, and additional patient characteristics. The model was estimated from randomized controlled trial data from 22 trials for statins and nonstatins. In 15 trials, the new time-dependent model had better predictions than cholesterol treatment trialists' estimations for a composite of coronary heart disease death, nonfatal myocardial infarction, and ischemic stroke. In explored scenarios, absolute risk reduction ≥2% with intensive treatment with high-intensity statin, ezetimibe, and high-dose proprotein convertase subtilisin/kexin type 9 inhibitor compared with high- or moderate-intensity statin alone were achieved in higher-risk populations with 2 to 5 years of treatment, and lower-risk populations with 9 to 11 years of treatment. Conclusions The time-dependent model accurately predicted treatment benefit seen from randomized controlled trials with a given lipid-lowering therapy by incorporating patient profile, timing, duration, and treatment type. The model can facilitate decision making and scenario analyses with a given lipid-lowering therapy strategy in various patient populations and time frames by providing an improved assessment of treatment benefit over time

Future in astroparticle physics and observational cosmology

This article is based on an introductory presentation at the 10th Pisa Meeting on Frontier Detectors for Frontier Physics at Elba in May 2006. A sample of results and expected future advances in the field of astroparticle physics are presented

The prototype detection unit of the KM3NeT detector

Submitted to EPJ CInternational audienceA prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80km offshore the Italian coast. KM3NeT in its final configuration will contain several hundreds of detection units. Each detection unit is a mechanical structure anchored to the sea floor, held vertical by a submerged buoy and supporting optical modules for the detection of Cherenkov light emitted by charged secondary particles emerging from neutrino interactions. This prototype string implements three optical modules with 31 photomultiplier tubes each. These optical modules were developed by the KM3NeT Collaboration to enhance the detection capability of neutrino interactions. The prototype detection unit was operated since its deployment in May 2014 until its decommissioning in July 2015. Reconstruction of the particle trajectories from the data requires a nanosecond accuracy in the time calibration. A procedure for relative time calibration of the photomultiplier tubes contained in each optical module is described. This procedure is based on the measured coincidences produced in the sea by the 40K background light and can easily be expanded to a detector with several thousands of optical modules. The time offsets between the different optical modules are obtained using LED nanobeacons mounted inside them. A set of data corresponding to 600 hours of livetime was analysed. The results show good agreement with Monte Carlo simulations of the expected optical background and the signal from atmospheric muons. An almost background-free sample of muons was selected by filtering the time correlated signals on all the three optical modules. The zenith angle of the selected muons was reconstructed with a precision of about 3{\deg}

The prototype detection unit of the KM3NeT detector: KM3NeT Collaboration

A prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80 km offshore the Italian coast. KM3NeT in its final configuration will contain several hundreds of detection units. Each detection unit is a mechanical structure anchored to the sea floor, held vertical by a submerged buoy and supporting optical modules for the detection of Cherenkov light emitted by charged secondary particles emerging from neutrino interactions. This prototype string implements three optical modules with 31 photomultiplier tubes each. These optical modules were developed by the KM3NeT Collaboration to enhance the detection capability of neutrino interactions. The prototype detection unit was operated since its deployment in May 2014 until its decommissioning in July 2015. Reconstruction of the particle trajectories from the data requires a nanosecond accuracy in the time calibration. A procedure for relative time calibration of the photomultiplier tubes contained in each optical module is described. This procedure is based on the measured coincidences produced in the sea by the $$^{40}$$40K background light and can easily be expanded to a detector with several thousands of optical modules. The time offsets between the different optical modules are obtained using LED nanobeacons mounted inside them. A set of data corresponding to 600 h of livetime was analysed. The results show good agreement with Monte Carlo simulations of the expected optical background and the signal from atmospheric muons. An almost background-free sample of muons was selected by filtering the time correlated signals on all the three optical modules. The zenith angle of the selected muons was reconstructed with a precision of about 3$$^\circ$$∘. © 2016, The Author(s)

Deep sea tests of a prototype of the KM3NeT digital optical module: KM3NeT Collaboration

The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deep waters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same40 K decay and the localisation of bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions

The prototype detection unit of the KM3NeT detector: KM3NeT Collaboration

A prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80 km offshore the Italian coast. KM3NeT in its final configuration will contain several hundreds of detection units. Each detection unit is a mechanical structure anchored to the sea floor, held vertical by a submerged buoy and supporting optical modules for the detection of Cherenkov light emitted by charged secondary particles emerging from neutrino interactions. This prototype string implements three optical modules with 31 photomultiplier tubes each. These optical modules were developed by the KM3NeT Collaboration to enhance the detection capability of neutrino interactions. The prototype detection unit was operated since its deployment in May 2014 until its decommissioning in July 2015. Reconstruction of the particle trajectories from the data requires a nanosecond accuracy in the time calibration. A procedure for relative time calibration of the photomultiplier tubes contained in each optical module is described. This procedure is based on the measured coincidences produced in the sea by the $$^{40}$$40K background light and can easily be expanded to a detector with several thousands of optical modules. The time offsets between the different optical modules are obtained using LED nanobeacons mounted inside them. A set of data corresponding to 600 h of livetime was analysed. The results show good agreement with Monte Carlo simulations of the expected optical background and the signal from atmospheric muons. An almost background-free sample of muons was selected by filtering the time correlated signals on all the three optical modules. The zenith angle of the selected muons was reconstructed with a precision of about 3$$^circ$$∘

Deep sea tests of a prototype of the KM3NeT digital optical module

250nonenoneAdrian-Martinez S; Ageron M; Aharonian F; Aiello S; Albert A; Ameli F; Anassontzis EG; Anghinolfi M; Anton G; Anvar S; Ardid M; de Asmundis R; Balasi K; Band H; Barbarino G; Barbarito E; Barbato F; Baret B; Baron S; Belias A; Berbee E; van den Berg AM; Berkien A; Bertin V; Beurthey S; van Beveren V; Beverini N; Biagi S; Bianucci S; Billault M; Birbas A; Rookhuizen HB; Bormuth R; Bouche V; Bouhadef B; Bourlis G; Bouwhuis M; Bozza C; Bruijn R; Brunner J; Cacopardo G; Caillat L; Calamai M; Calvo D; Capone A; Caramete L; Caruso F; Cecchini S; Ceres A; Cereseto R; Champion C; Chateau F; Chiarusi T; Christopoulou B; Circella M; Classen L; Cocimano R; Colonges S; Coniglione R; Cosquer A; Costa M; Coyle P; Creusot A; Curtil C; Cuttone G; D'Amato C; D'Amico A; De Bonis G; De Rosa G; Deniskina N; Destelle JJ; Distefano C; Donzaud C; Dornic D; Dorosti-Hasankiadeh Q; Drakopoulou E; Drouhin D; Drury L; Durand D; Eberl T; Eleftheriadis C; Elsaesser D; Enzenhofer A; Fermani P; Fusco LA; Gajana D; Gal T; Galata S; Gallo F; Garufi F; Gebyehu M; Giordano V; Gizani N; Ruiz RG; Graf K; Grasso R; Grella G; Grmek A; Habel R; van Haren H; Heid T; Heijboer A; Heine E; Henry S; Hernandez-Rey JJ; Herold B; Hevinga MA; van der Hoek M; Hofestadt J; Hogenbirk J; Hugon C; Hoessl J; Imbesi M; James C; Jansweijer P; Jochum J; de Jong M; Kadler M; Kalekin O; Kappes A; Kappos E; Katz U; Kavatsyuk O; Keller P; Kieft G; Koffeman E; Kok H; Kooijman P; Koopstra J; Korporaal A; Kouchner A; Koutsoukos S; Kreykenbohm I; Kulikovskiy V; Lahmann R; Lamare P; Larosa G; Lattuada D; Le Provost H; Leisos A; Lenis D; Leonora E; Clark ML; Liolios A; Alvarez CDL; Lohner H; Lo Presti D; Louis F; Maccioni E; Mannheim K; Manolopoulos K; Margiotta A; Maris O; Markou C; Martinez-Mora JA; Martini A; Masullo R; Michael T; Migliozzi P; Migneco E; Miraglia A; Mollo C; Mongelli M; Morganti M; Mos S; Moudden Y; Musico P; Musumeci M; Nicolaou C; Nicolau CA; Orlando A; Orzelli A; Papageorgiou K; Papaikonomou A; Papaleo R; Pavalas GE; Peek H; Pellegrino C; Pellegriti MG; Perrina C; Petridou C; Piattelli P; Pikounis K; Popa V; Pradier T; Priede M; Puhlhofer G; Pulvirenti S; Racca C; Raffaelli F; Randazzo N; Rapidis PA; Razis P; Real D; Resvanis L; Reubelt J; Riccobene G; Rovelli A; Royon J; Saldana M; Samtleben DFE; Sanguineti M; Santangelo A; Sapienza P; Savvidis I; Schmelling J; Schnabel J; Sedita M; Seitz T; Sgura I; Simeone F; Siotis I; Sipala V; Solazzo M; Spitaleri A; Spurio M; Stavropoulos G; Steijger J; Stolarczyk T; Stransky D; Taiuti M; Terreni G; Tezier D; Theraube S; Thompson LF; Timmer P; Trapierakis HI; Trasatti L; Trovato A; Tselengidou M; Tsirigotis A; Tzamarias S; Tzamariudaki E; Vallage B; Van Elewyck V; Vermeulen J; Vernin P; Viola S; Vivolo D; Werneke P; Wiggers L; Wilms J; de Wolf E; van Wooning RHL; Yatkin K; Zachariadou K; Zonca E; Zornoza JD; Zuniga J; Zwart AAdrian-Martinez, S; Ageron, M; Aharonian, F; Aiello, S; Albert, A; Ameli, F; Anassontzis, Eg; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; de Asmundis, R; Balasi, K; Band, H; Barbarino, G; Barbarito, E; Barbato, F; Baret, B; Baron, S; Belias, A; Berbee, E; van den Berg, Am; Berkien, A; Bertin, V; Beurthey, S; van Beveren, V; Beverini, N; Biagi, S; Bianucci, S; Billault, M; Birbas, A; Rookhuizen, Hb; Bormuth, R; Bouche, V; Bouhadef, B; Bourlis, G; Bouwhuis, M; Bozza, C; Bruijn, R; Brunner, J; Cacopardo, G; Caillat, L; Calamai, M; Calvo, D; Capone, A; Caramete, L; Caruso, F; Cecchini, S; Ceres, A; Cereseto, R; Champion, C; Chateau, F; Chiarusi, T; Christopoulou, B; Circella, M; Classen, L; Cocimano, R; Colonges, S; Coniglione, R; Cosquer, A; Costa, M; Coyle, P; Creusot, A; Curtil, C; Cuttone, G; D'Amato, C; D'Amico, A; De Bonis, G; De Rosa, G; Deniskina, N; Destelle, Jj; Distefano, C; Donzaud, C; Dornic, D; Dorosti-Hasankiadeh, Q; Drakopoulou, E; Drouhin, D; Drury, L; Durand, D; Eberl, T; Eleftheriadis, C; Elsaesser, D; Enzenhofer, A; Fermani, P; Fusco, La; Gajana, D; Gal, T; Galata, S; Gallo, F; Garufi, F; Gebyehu, M; Giordano, V; Gizani, N; Ruiz, Rg; Graf, K; Grasso, R; Grella, G; Grmek, A; Habel, R; van Haren, H; Heid, T; Heijboer, A; Heine, E; Henry, S; Hernandez-Rey, Jj; Herold, B; Hevinga, Ma; van der Hoek, M; Hofestadt, J; Hogenbirk, J; Hugon, C; Hoessl, J; Imbesi, M; James, C; Jansweijer, P; Jochum, J; de Jong, M; Kadler, M; Kalekin, O; Kappes, A; Kappos, E; Katz, U; Kavatsyuk, O; Keller, P; Kieft, G; Koffeman, E; Kok, H; Kooijman, P; Koopstra, J; Korporaal, A; Kouchner, A; Koutsoukos, S; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lamare, P; Larosa, G; Lattuada, D; Le Provost, H; Leisos, A; Lenis, D; Leonora, E; Clark, Ml; Liolios, A; Alvarez, Cdl; Lohner, H; Lo Presti, D; Louis, F; Maccioni, E; Mannheim, K; Manolopoulos, K; Margiotta, A; Maris, O; Markou, C; Martinez-Mora, Ja; Martini, A; Masullo, R; Michael, T; Migliozzi, P; Migneco, E; Miraglia, A; Mollo, C; Mongelli, M; Morganti, M; Mos, S; Moudden, Y; Musico, P; Musumeci, M; Nicolaou, C; Nicolau, Ca; Orlando, A; Orzelli, A; Papageorgiou, K; Papaikonomou, A; Papaleo, R; Pavalas, Ge; Peek, H; Pellegrino, C; Pellegriti, Mg; Perrina, C; Petridou, C; Piattelli, P; Pikounis, K; Popa, V; Pradier, T; Priede, M; Puhlhofer, G; Pulvirenti, S; Racca, C; Raffaelli, F; Randazzo, N; Rapidis, Pa; Razis, P; Real, D; Resvanis, L; Reubelt, J; Riccobene, G; Rovelli, A; Royon, J; Saldana, M; Samtleben, Dfe; Sanguineti, M; Santangelo, A; Sapienza, P; Savvidis, I; Schmelling, J; Schnabel, J; Sedita, M; Seitz, T; Sgura, I; Simeone, F; Siotis, I; Sipala, V; Solazzo, M; Spitaleri, A; Spurio, M; Stavropoulos, G; Steijger, J; Stolarczyk, T; Stransky, D; Taiuti, M; Terreni, G; Tezier, D; Theraube, S; Thompson, Lf; Timmer, P; Trapierakis, Hi; Trasatti, L; Trovato, A; Tselengidou, M; Tsirigotis, A; Tzamarias, S; Tzamariudaki, E; Vallage, B; Van Elewyck, V; Vermeulen, J; Vernin, P; Viola, S; Vivolo, D; Werneke, P; Wiggers, L; Wilms, J; de Wolf, E; van Wooning, Rhl; Yatkin, K; Zachariadou, K; Zonca, E; Zornoza, Jd; Zuniga, J; Zwart,