Sedimentation and fouling of optical surfaces at the ANTARES site
Astroparticle Physics 19:2 (2003) 253-267
Abstract:
ANTARES is a project leading towards the construction and deployment of a neutrino telescope in the deep Mediterranean Sea. The telescope will use an array of photomultiplier tubes to detect the Cherenkov light emitted by muons resulting from the interaction with matter of high energy neutrinos. In the vicinity of the deployment site the ANTARES Collaboration has performed a series of in situ measurements to study the change in light transmission through glass surfaces during immersions of several months. The average loss of light transmission is estimated to be only ∼2% at the equator of a glass sphere one year after deployment. It decreases with increasing zenith angle, and tends to saturate with time. The transmission loss, therefore, is expected to remain small for the several year lifetime of the ANTARES detector whose optical modules are oriented downwards. The measurements were complemented by the analysis of the 210 Pb activity profile in sediment cores and the study of biofouling on glass plates. Despite a significant sedimentation rate at the site, in the 0.02-0.05 cm yr -1 range, the sediments adhere loosely to the glass surfaces and can be washed off by water currents. Further, fouling by deposits of light-absorbing particulates is only significant for surfaces facing upwards. © 2002 Elsevier Science B.V. All rights reserved.The analog ring sampler: An ASIC for the front-end electronics of the ANTARES neutrino telescope
IEEE Transactions on Nuclear Science 49 II:3 (2002) 1122-1129
Abstract:
The ANTARES detector is a 0.1-km2-scale high-energy neutrino telescope. It will be located in the Mediterranean Sea at a depth of 2400 m. It consists of a matrix of optical modules each containing a photomultiplier tube. An ASIC named the Analog Ring Sampler has been developed to process photomultiplier tube signals. It measures their arrival time and their charge and samples their shape when this differs from that characteristic of single photoelectrons. The digital output is multiplexed and transmitted to the shore through further electronics and an optical link. The main circuit blocks of the ASIC are discussed in this paper.The ANTARES optical module
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 484:1-3 (2002) 369-383
Abstract:
The ANTARES collaboration is building a deep sea neutrino telescope in the Mediterranean Sea. This detector will cover a sensitive area of typically 0.1 km2 and will be equipped with about 1000 optical modules. Each of these optical modules consists of a large area photomultiplier and its associated electronics housed in a pressure resistant glass sphere. The design of the ANTARES optical module, which is a key element of the detector, has been finalized following extensive R&D studies and is reviewed here in detail. © 2001 Elsevier Science B.V. All rights reserved.Background light in potential sites for the ANTARES undersea neutrino telescope
Astroparticle Physics 13:2-3 (2000) 127-136
Abstract:
The ANTARES collaboration has performed a series of in-situ measurements to study the background light for a planned undersea neutrino telescope. Such background can be caused by 40K decays or by biological activity. We report on measurements at two sites in the Mediterranean Sea at depths of 2400 m and 2700 m, respectively. Three photomultiplier tubes were used to measure single counting rates and coincidence rates for pairs of tubes at various distances. The background rate is seen to consist of three components: a constant rate due to 40K decays, a continuum rate that varies on a time scale of several hours simultaneously over distances up to at least 40 m, and random bursts a few seconds long that are only correlated in time over distances of the order of a meter. A trigger requiring coincidences between nearby photomultiplier tubes should reduce the trigger rate for a neutrino telescope to a manageable level with only a small loss in efficiency. © 2000 Elsevier Science B.V.The ANTARES project
NUCL PHYS B-PROC SUP 75A (1999) 415-417