Deep-Underwater Cherenkov Detector in Lake Baikal Avrorin, A.V.; Avrorin, A. D.; Ayinutdinov, V. M. ...
Journal of experimental and theoretical physics,
04/2022, Letnik:
134, Številka:
4
Journal Article
Recenzirano
Neutrino telescope Baikal-CVD is a deep-underwater Cherenkov detector of elementary particles of the 1-km
3
scale, which has been developed beginning from 2016 in Lake Baikal. The telescope is ...assembled from separate blocks (clusters of optical modules), which makes it possible to perform scientific research even at early stages of its development. In the 2021 configuration, the detector contains eight clusters with 2304 optical modules in total and is the largest neutrino telescope in the Northern hemisphere. The design and main characteristics of the Baikal-GVD data acquisition system are described, the problems of deep-underwater engineering associated with the development of the detector are considered, and some physical results obtained on the facility are presented
The Baikal-GVD deep underwater neutrino experiment participates in the international multi-messenger program to detect the astrophysical sources of high- and ultrahigh-energy cosmic-ray particles, ...being at the stage of array deployment and a step-by-step increase of the telescope’s effective volume to the scale of a cubic kilometer. At present, the telescope consists of seven clusters containing 2016 photodetectors. The effective volume of the detector has reached 0.35 km
for the selection of shower events from neutrino interactions in Baikal water. The experimental data have been accumulated in a continuous exposure mode since 2015, allowing a prompt data analysis and a celestial-sphere monitoring program to be implemented in real time. We discuss the structure of the data acquisition system, describe the physical event reconstruction procedure in the mode of fast response to alerts, and present the results of our analysis of nine alerts from the polar IceCube telescope from early September to late October 2020.
The films of amorphous hydrogenated carbon doped with Si and O were deposited onto the sample of crystalline silicon by method of plasma-chemical deposition in the mix of polyphenyl methylsiloxane ...vapors and argon. Physico-mechanical and optical properties of films were examined for their use as anti-reflection and protective coatings in infrared optics devices. Film transparency in the wavelength range of 2.5–8 μm was measured by method of infrared spectroscopy with a Fourier transform. The structure and composition of films were studied by methods of Raman and X-ray photoelectron spectroscopy. Hardness and other mechanical properties of films were determined by nanoindentation. It was shown that the double-sided deposition of a-C:H:SiO
x
films onto Si plates allows increasing their integrated transmission in the wavelength region of 3– 5 μm from 50 to 87%. The films possess excellent mechanical characteristics, thermal stability in the temperature range from room temperature to 500°С, and resistance to aqueous solutions of salt.
The Baikal-GVD project aims to create a deep-water neutrino telescope on a cubic kilometer scale in Lake Baikal. The telescope is at the rollout stage; its effective volume for detecting showers from ...high-energy neutrinos of an astrophysical nature has reached 0.25 km
3
. A set of experimental data on the telescope has been acquired since 2015 in the constant exposure mode simultaneously with the build-up of the detector. This article is devoted to the calibration of the measuring system of the neutrino telescope. It presents the equipment of the calibration system, describes the calibration procedure, and discusses the issues of the accuracy, reliability, and effectiveness of the developed calibration procedures.
Current status of the BAIKAL-GVD project Avrorin, A.V.; Aynutdinov, V.M.; Belolaptikov, I.A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2013, Letnik:
725
Journal Article
Recenzirano
We present a status of the Baikal-GVD Project. The objective of this project is a construction of a km3-scale neutrino telescope in the Lake Baikal. As an important milestone, the first GVD ...engineering array has been deployed and ran in April, 2011. Application of a completely new technology gave us an opportunity to study all the basic elements of the future full detector and to finalize the GVD technical design. We discuss the configuration and the design of the engineering array as well as data performance with the preliminary results.
The prototyping/early construction phase of the BAIKAL-GVD project Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Letnik:
742
Journal Article
Recenzirano
Odprti dostop
The prototyping phase of the BAIKAL-GVD project has been started in April 2011 with the deployment of a three string engineering array which comprises all basic elements and systems of the Gigaton ...Volume Detector (GVD) in Lake Baikal. In April 2012 the version of engineering array which comprises the first full-scale string of the GVD demonstration cluster had been deployed and operated during 2012. The first stage of the GVD-cluster which consists of three strings was deployed in April 2013. We review the prototyping phase of the BAIKAL-GVD project and describe the configuration and design of the 2013 engineering array.
Display omitted
•TiO2 and N-doped TiO2 films were deposited and annealed.•N-doping and annealing led to the film phase transition.•Band gap energy of annealed films decreased with increasing N-doping ...level.•Wettability improved upon annealing as well as N-doping.
Titanium dioxide film is one of the most promising self-cleaning materials. The self-cleaning performance is directly related to the photocatalytic activity and surface wettability, which, in turn, depends on the TiO2 film structure parameters. Nitrogen-doping and post annealing are commonly used for TiO2 film treatment. The present paper addresses the mechanisms of N-doping and annealing induced TiO2 film structure transition, band gap narrowing and wettability transition. It is shown that N-doping combined with annealing leads to anatase → rutile phase transition, formation of hierarchical topography, change of surface chemical composition, and consequently results in reduction of band gap energy and water contact angle. N-doping level and N-linkages are found to significantly affect the structure/properties of annealed TiO2 and N-doped TiO2 films. The proposed mechanisms might help optimize TiO2 film synthesis and post treatment procedures. Moreover, annealed N-doped TiO2 film with highest N-content, simultaneously exhibiting anatase-rutile polycrystalline structure, high roughness, as well as lowest band gap energy and water contact angle, is supposed to present optimal self-cleaning performance.
We have analyzed the neutrino events recoded in the deep-water neutrino experiment NT200 in Lake Baikal in five years of observations toward dark dwarf spheroidal galaxies (dSphs) in the southern ...hemisphere and the Large Magellanic Cloud (LMC). This analysis completes the series of works based on NT200 data in the search for a dark matter annihilation signal in astrophysical objects. We have found no significant excess in the number of observed events relative to the expected background from atmospheric neutrinos in all tested directions, in 22 dSphs and the LMC. For a sample of five selected dwarf galaxies we have performed a joint analysis of the data by the maximum likelihood method. We have obtained a correspondence of the observational data to the null hypothesis about the presence of only background events and established 90% confidence-level upper limits for the annihilation cross sections of dark matter particles with a mass from 30 GeV to 10 TeV in several annihilation channels both in the joint analysis of the selected sample of galaxies and in the analysis toward the LMC. The strongest constraints at a level of 7 × 10
–21
cm
3
s
–1
have been obtained for the direction toward the LMC in the channel of annihilation into a pair of neutrinos.
Status of the Baikal-GVD project Avrorin, A.V.; Aynutdinov, V.M.; Bannasch, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2012, Letnik:
692
Journal Article
Recenzirano
Odprti dostop
The construction of a km3-scale neutrino telescope – the Gigaton Volume Detector (GVD) in Lake Baikal – is the central goal of the Baikal collaboration. During the R&D phase of the GVD project in ...2008–2010 years the basic elements of GVD – new optical modules, FADC readout units, underwater communications and trigger systems – have been developed, produced and tested in situ by long-term operating prototype strings in Lake Baikal. The prototyping phase of the GVD project has been started in April 2011 with the installation of a three string array (prototype cluster) which comprises all basic elements and systems of the GVD-telescope in Lake Baikal. We describe configuration and technical design of the GVD, present selected results obtained during 2008–2010 with prototype strings, and describe configuration and design of the 2011 prototype cluster.
The Prototyping phase of the BAIKAL-GVD project has been started in April 2011 with the deployment of first autonomous engineering array which comprises all basic elements and systems of the Gigaton ...Volume Detector (GVD) in Lake Baikal. The prototyping phase will be concluded with deployment of the GVD demonstration cluster “DUBNA” in 2015, which will comprise 192 light sensors arranged at 8 strings. The first stage of the GVD demonstration cluster which consists of three strings was deployed in April 2013 and successfully operated up to February 2014. We review the prototyping phase of the BAIKAL-GVD project and describe the configuration and design of the 2013 engineering array.
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