ANTARES is a deep-sea, large volume Mediterranean neutrino telescope installed off the Coast of Toulon, France. It is taking data in its complete configuration since May 2008 with nearly 900 photomultipliers installed on 12 lines. It is today the largest high energy neutrino telescope of the northern hemisphere. The charge calibration and threshold tuning of the photomultipliers and their associated front-end electronics is of primary importance. It indeed enables to translate signal amplitudes into number of photo-electrons which is the relevant information for track and energy reconstruction. It has therefore a strong impact on physics analysis. We will present the performances of the front-end chip, so-called ARS, including the waveform mode of acquisition. The in-laboratory as well as regularly performed in situ calibrations will be presented together with related studies like the time evolution of the gain of photomultipliers
The ANTARES detector is a Cherenkov underwater neutrino telescope operating in the Mediterranean Sea. Its construction was completed in 2008. Even though optimised for the search of cosmic neutrinos, this telescope is also sensitive to nuclearites (massive nuggets of strange quark matter) trough the black body radiation emitted along their path. We discuss here the possible detection of non-relativistic down-going nuclearites with the ANTARES telescope and present the results of an analysis using data collected from 2009 till 2017.
ANTARES is the largest undersea neutrino telescope and it has been taking data in its final configuration for more than ten years. On their journey to the Earth, cosmic rays can be absorbed by celestial objects, like the Sun, leading to a deficit in the atmospheric muon flux measured by the ANTARES detector, the so-called Sun "shadow" effect. This phenomenon can be used to evaluate fundamental telescope characteristics: the detector angular resolution and pointing accuracy. This work describes the study of the Sun "shadow" effect using the ANTARES data collected between 2008 and 2017. The stat…
At about 40 km off the coast of Toulon (France), anchored at 2475 m deep in the Mediterranean Sea, there is ANTARES: the first undersea neutrino telescope and the only one currently operating. The detector consists of 885 photomultiplier tubes arranged into 12 strings of 450-metres high, with the aim to detect the Cherenkov light induced by the charged superluminal interaction products of neutrinos. Its main scientific target is the search for high-energy (TeV and beyond) neutrinos from cosmic accelerators, as predicted by hadronic interaction models, and the measurement of the cosmic neutrino…
Performance of the front-end electronics of the ANTARES neutrino telescope
ANTARES是安装在地中海2，475米深处的高能中微子望远镜。它由一个三维阵列的光学模块，每个模块包含一个大的光电倍增管。总共有2700个名为Answer Ring Sampler（ARS）的前端ASIC处理光电管信号，测量它们的到达时间，幅度和形状，以及执行监控和校准任务。ARS芯片处理来自光学模块的模拟信号，并将信息转换为数字数据。所有信息都通过进一步的多路复用电子设备和光学链路传输到岸上。本文介绍了ARS芯片的性能;总结了实验室功能和特性测试的结果，并说明了该设备的长期性能。
The ANTARES detector is an undersea neutrino telescope in the Mediterranean Sea. The search for point-like neutrino sources is one of the main goals of the ANTARES telescope, requiring a reliable method to evaluate the detector angular resolution and pointing accuracy. This work describes the study of the Sun "shadow" effect with the ANTARES detector. The shadow is the deficit in the atmospheric muon flux in the direction of the Sun caused by the absorption of the primary cosmic rays. This analysis is based on the data collected between 2008 and 2017 by the ANTARES telescope. The observed stat…
Studies of Acoustic Neutrino Detection Methods with ANTARES
从宇宙中的极高能量现象可以预测中微子在很宽的能量范围内的发射。即使是目前或下一代切伦科夫中微子望远镜可能太小，无法探测到能量超过EeV尺度的宇宙中微子的微弱通量。声学探测方法是一个很有前途的选择，以扩大在这个最高能量的制度的发现潜力。在未来可能的深海探测器中，中微子相互作用产生的压力波可以由100 km 3大小的声学传感器阵列探测到，即使它稀疏地配备了大约100个传感器/km 3。本文重点介绍AMADEUS声学传感器的设置，它是ANTARES探测器的一个组成部分。该项目的主要目的是对未来的声学中微子探测器进行可行性研究。然而，从ANTARES-AMADEUS混合光声装置中获得的经验也可以转移到未来的超大体积光学中微子望远镜中，特别是用于使用声学传感器的探测器结构的位置校准。
Papers on the searches for dark matter and exotics, neutrino oscillations and detector calibration, prepared for the 35th International Cosmic Ray Conference (ICRC 2017, Busan, South Korea) by the ANTARES Collaboration
One of the main objectives of the ANTARES telescope is the search for point-like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context and a reliable way to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i.e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, the Moon shadow is observed with $3.5σ$ statistical significance…
Monte Carlo simulations are a unique tool to check the response of a detector and to monitor its performance. For a deep-sea neutrino telescope, the variability of the environmental conditions that can affect the behaviour of the data acquisition system must be considered, in addition to a reliable description of the active parts of the detector and of the features of physics events, in order to produce a realistic set of simulated events. In this paper, the software tools used to produce neutrino and cosmic ray signatures in the telescope and the strategy developed to represent the time evolu…
The ANTARES experiment consists of an array of photomultipliers distributed along 12 lines and located deep underwater in the Mediterranean Sea. It searches for astrophysical neutrinos collecting the Cherenkov light induced by the charged particles, mainly muons, produced in neutrino interactions around the detector. Since at energies of $\sim$10 TeV the muon and the incident neutrino are almost collinear, it is possible to use the ANTARES detector as a neutrino telescope and identify a source of neutrinos in the sky starting from a precise reconstruction of the muon trajectory. To get this re…
The Arizona-NOAO Temporal Analysis and Response to Events System (ANTARES) is a joint project of the National Optical Astronomy Observatory and the Department of Computer Science at the University of Arizona. The goal is to build the software infrastructure necessary to process and filter alerts produced by time-domain surveys, with the ultimate source of such alerts being the Large Synoptic Survey Telescope (LSST). The ANTARES broker will add value to alerts by annotating them with information from external sources such as previous surveys from across the electromagnetic spectrum. In addition…
A search for cosmic neutrino sources using the data collected with the ANTARES neutrino telescope between early 2007 and the end of 2015 is performed. For the first time, all neutrino interactions --charged and neutral current interactions of all flavours-- are considered in a search for point-like sources with the ANTARES detector. In previous analyses, only muon neutrino charged current interactions were used. This is achieved by using a novel reconstruction algorithm for shower-like events in addition to the standard muon track reconstruction. The shower channel contributes about 23\% of al…
Cherenkov light induced by radioactive decay products is one of the major sources of background light for deep-sea neutrino telescopes such as ANTARES. These decays are at the same time a powerful calibration source. Using data collected by the ANTARES neutrino telescope from mid 2008 to 2017, the time evolution of the photon detection efficiency of optical modules is studied. A modest loss of only 20% in 9 years is observed. The relative time calibration between adjacent modules is derived as well.
ANTARES is currently the largest undersea neutrino telescope, located in the Mediterranean Sea and taking data since 2007. It consists of a 3D array of photo sensors, instrumenting about 10Mt of seawater to detect Cherenkov light induced by secondary particles from neutrino interactions. The event reconstruction and background discrimination is challenging and machine-learning techniques are explored to improve the performance. In this contribution, two case studies using deep convolutional neural networks are presented. In the first one, this approach is used to improve the direction reconstr…
We develop a novel technique to exploit the extensive data sets provided by underwater neutrino telescopes to gain information on bioluminescence in the deep sea. The passive nature of the telescopes gives us the unique opportunity to infer information on bioluminescent organisms without actively interfering with them. We propose a statistical method that allows us to reconstruct the light emission of individual organisms, as well as their location and movement. A mathematical model is built to describe the measurement process of underwater neutrino telescopes and the signal generation of the …
AMADEUS - The Acoustic Neutrino Detection Test System of the ANTARES Deep-Sea Neutrino Telescope
本文介绍的AMADEUS（ANTARES Modules for the Acoustic Detection Under the Sea）系统旨在研究深海中微子的声学探测技术。它被集成到地中海的ANTARES中微子望远镜中。其声学传感器安装在水深2 050米至2 300米之间，采用压电元件，用于宽带记录频率高达125千赫的信号。传感器的典型灵敏度约为-145 dB re 1V/muPa（包括1V）。AMADEUS于2008年5月完成，由六个“声学集群”组成，每个集群由六个声学传感器组成，相互之间的距离约为1米。ANTARES探测器的两个垂直机械结构（所谓的线路）各有三个声学集群。集群之间的间距从14.5米到340米不等。每个集群都包含定制设计的电子板，用于放大和数字化来自传感器的声学信号。岸上计算机集群用于处理和过滤数据流并存储所选择的事件。每天记录的数据量约为10 GB。该系统连续自动运行，只需要很少的人为干预。AMADEUS允许对深海中的瞬态信号和环境噪声以及几个长度尺度上的信号相关性和声学点源的定位进行广泛的研究。因此，该系统非常适合于评估背景条件的双极脉冲的测量预期起源于中微子相互作用。
Muons created by $ν_μ$ charged current (CC) interactions in the water surrounding the ANTARES neutrino telescope have been almost exclusively used so far in searches for cosmic neutrino sources. Due to their long range, highly energetic muons inducing Cherenkov radiation in the water are reconstructed with dedicated algorithms that allow the determination of the parent neutrino direction with a median angular resolution of about \unit{0.4}{\degree} for an $E^{-2}$ neutrino spectrum. In this paper, an algorithm optimised for accurate reconstruction of energy and direction of shower events in th…
The gSeaGen code is a GENIE based application to generate neutrino-induced events in an underwater neutrino detector. The gSeaGen code is able to generate events induced by all neutrino flavours, taking into account topological differences between track-type and shower-like events. The neutrino interaction is simulated taking into account the density and the composition of the media surrounding the detector. The main features of gSeaGen will be presented together with some examples of its application within ANTARES and KM3NeT.
