The optical module of Baikal-GVD

In April 2015, the first cluster of Baikal-GVD was deployed in Lake Baikal and put into operation. It comprises eight strings. Each string consists of 24 optical modules. An optical module is a detection element of Baikal-GVD; it includes a Hamamatsu R7081-100 photomultiplier tube with a high quantum sensitivity. We describe the design of the optical module, the front-end electronics, and the laboratory characterization and calibration.     

Radiation of waves by a sphere harmonically oscillating to-and-fro in a viscous medium

The theory of the radiation of sound by a sphere in an ideal medium is presented in detail in [1–3]. The emission of waves by a sphere oscillating to-and-fro in a viscous incompressible liquid is analyzed in [4, 5]. The present paper gives a precise solution to the problem of the radiation of sound by a sphere oscillating in a viscous medium.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 101–106, September–October, 1970.     

Tunka-133: Status 2008 and development of methods for data analysis

The activity on creation of a array with an area of 1 km² for recording extensive air showers using Cherenkov light began in the Tunka valley in 2006. The new array will allow one to study cosmic rays in the energy range 10¹⁵–10¹⁸ eV by the unified method. In the winter of 2007–2008, the array operated with 4 clusters, 7 detectors in each cluster. Experimental data obtained during 270 h of fair weather in moonless nights demonstrated unique capabilities of the new array, related with the possibility of recording the pulse shape with a step of 5 ns from each detector.     

Vibrations of a fan jet in running a supersonic jet into a notched obstacle

Some kinds of vibrations of a fan jet are described. A physical model of one kind of self-excited vibrations of the fan jet is formulated. The formulas to calculate the frequencies of self-excited vibrations are given. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 4, pp. 118–124, July–August, 1999.     

Data acquisition system for the Baikal-GVD neutrino telescope

The objective of the Baikal-GVD project is the construction of a km³-scale neutrino telescope in Lake Baikal. The Gigaton Volume Detector consists of a large three-dimensional array of photo-multiplier tubes. The first GVD-cluster has been deployed and commissioned in April 2015. The data acquisition system (DAQ) of the detector takes care of the digitization of the photo-multiplier tube signals, data transmission, filtering and storage. The design and the implementation of the data acquisition system are described.