A.V. Avrorin

Search for high-energy neutrinos in the Baikal neutrino experiment

A new analysis of the data from the NT200 neutrino telescope based on the reconstruction of parameters for high-energy showers generated in neutrino interactions has yielded new upper limits on the diffuse neutrino fluxes predicted by a number of theoreticalmodels. The upper limit on the all-flavor neutrino flux with an energy spectrum E−2 is E2Φν < 2.9 × 10−7 GeV cm−2 s−1 sr−1.

The prototyping/early construction phase of the BAIKAL-GVD project

Abstract 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.

Search for Neutrinos from Gamma-Ray Bursts with the Baikal Neutrino Telescope NT200

We present the results of our search for neutrino events coinciding in time and direction with gamma-ray bursts (GRBs) with the Baikal underwater neutrino telescope NT200. No events confirming a neutrino accompaniment of GRBs have been detected. Model-independent limits (Greens function) on the neutrino flux from GRBs have been obtained. For the Waxman-Bahcall neutrino spectrum, the limit on the neutrino flux from a GRB has been found to be Eν2Φν ⩽ 1.1 × 10−6 GeV cm−2 s−1 sr−1.

Sensitivity of the Baikal-GVD neutrino telescope to neutrino emission toward the center of the galactic dark matter halo

We analyze sensitivity of the gigaton volume telescope Baikal-GVD for detection of neutrino signal from dark matter annihilations or decays in the Galactic Center. Expected bounds on dark matter annihilation cross section and its lifetime are found for several annihilation/decay channels.

An experimental string of the NT1000 Baikal neutrino telescope

A project of the NT1000 deep-water neutrino telescope with an effective volume of ∼1 km3 is currently being developed by the BAIKAL collaboration. The telescope will be located in Lake Baikal in close vicinity of the NT200+ detector, which is currently in operation. The telescope will be composed of 12 clusters with 8 similar strings of optical modules in each (each string has two sections of the NT1000 optical modules). The section of the NT1000 optical modules has been developed using higher-efficiency photomultiplier tubes and state-of-the-art electronics. The field tests of the experimental string consisting of two sections with six optical modules in each have been performed. The results of these investigations are used in the project of the NT1000 neutrino telescope and in the hydrological study of Lake Baikal.

Status and recent results of the BAIKAL-GVD project

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.

Data acquisition system of the NT1000 Baikal neutrino telescope

In April of 2013, the first stage of the experimental cluster of the NT1000 deep-water neutrino telescope consisting of three strings with 24 optical modules in each was installed at Lake Baikal and switched on in the continuous exposure mode. The detection and data acquisition systems of this setup are described.

A hydroacoustic positioning system for the experimental cluster of the cubic-kilometer-scale neutrino telescope at Lake Baikal

The NT1000 deep-water neutrino telescope with an effective volume of ∼2 km3 is currently being developed at Lake Baikal by the BAIKAL collaboration. The telescope will be composed of functionally independent setups—clusters of strings of optical modules based on photomultiplier tubes (with eight strings in each cluster). Since 2011, field tests of the basic elements and systems of the future telescope included in autonomous measuring complexes—prototypes of the NT1000 cluster—have been performed at Lake Baikal. The basic elements and the layout of one of the currently considered versions of the acoustic positioning system for the NT1000 telescope are described, and results of tests of the system prototype included as a component in the experimental cluster of the year 2012 are presented.

Search for astrophysical neutrinos in the Baikal neutrino project

The currently running NT200 and NT200+ Baikal neutrino telescopes and the prospects for development of the Baikal Neutrino Project are briefly descr⇊ed. Preliminary results of the search for neutrino events correlated with cosmological gamma-ray bursts at the NT200 are presented. The feasibility of developing a method for acoustic detection of ultrahigh-energy neutrinos in the Baikal Neutrino Project is discussed. The calculation results for the energy spectrum and zenith-angle distributions of atmospheric neutrinos in the energy range from 10 to 107 GeV obtained within various high-energy hadron-nucleus interaction models are presented.

Present status of the BAIKAL-GVD project development

We present a current status of the Baikal-GVD Project. The objective of this project is a construction of a km3-scale neutrino telescope in the Baikal lake. Set of prototype arrays which were installed and operated during 2009-2011 in Lake Baikal allowed to study all basic elements of the future full detector and to finalize the GVD technical design. We discuss the configuration and the design of the engineering arrays as well as DAQ performance and the preliminary results.