Searching for Neutrino and Ultra-High-Energy Gamma-Ray Counterparts of the GCN Alerts

Physics of Atomic Nuclei - The Baksan Neutrino Observatory setups are currently performing search for neutrino and ultra-high-energy gamma-ray counterparts of the events on the Gamma-ray...     

Search for Electron Neutrinos from Gravitational Wave Events at the Baksan Underground Scintillation Telescope

In the data obtained at the Baksan underground scintillation telescope (BUST), electron neutrinos and antineutrinos with energies above 21 MeV have been sought in coincidence with the GW150914, GW151226, GW170104, GW170608, GW170814, and GW170817 gravitational wave events. No neutrino signals from gravitational wave events have been detected in the interval of ±500 s at the Baksan underground scintillation telescope. Bounds on the fluxes of low-energy electron neutrinos and antineutrinos from astrophysical sources of gravitational bursts have been obtained.     

Effect of the doping level on temperature bistability in a silicon wafer

The influence of the doping level on the effect of the temperature bistability in a silicon wafer upon radiative heat transfer between the wafer and the elements of the heating system is studied. Theoretical transfer characteristics are constructed for a silicon wafer doped with donor and acceptor impurities. These characteristics are compared with the transfer characteristics obtained during heating and cooling of wafers with the hole conduction (with dopant concentrations of 10¹⁵, 2 × 10¹⁶, and 3 × 10¹⁷ cm^?3) and electron conduction (with impurity concentrations of 10¹⁵ and 8 × 10¹⁸ cm^?3) in a thermal reactor of the rapid thermal annealing setup. It is found that the width and height of the hysteresis loop decrease with increasing dopant concentration and are almost independent of the type of conduction of the silicon wafer. The critical value of the impurity concentration of both types is 1.4 × 10¹⁷ cm^?3. For this concentration, the loop width vanishes, and the height corresponds to the minimal value of the temperature jump (～200 K). The mechanism of temperature bistability in the silicon wafer upon radiative heat transfer is discussed.     

The Carpet-3 EAS Array for Investigation of Gamma-Radiation with Energy $$\boldsymbol{E>100}$$ TeV

Physics of Atomic Nuclei - The Carpet-3 experiment for investigation of gamma radiation with energy above 100 TeV is currently being prepared at the Baksan Neutrino Observatory of the Institute for...     

Scintillation detector with SiPM matrix as a photosensor

The results of a characterization study of the scintillation detector with SiPM matrices as multichannel photosensors are presented. The SiPM matrix attached to a plastic scintillator gives a snapshot of the glowing track of a charged particle traversing the scintillator.     

Synthesis of a hybrid material from CdS nanoparticles and carbon nanotubes

A method for synthesis of a hybrid material from CdS nanoparticles and carbon nanotubes (CNT) by the precipitation of CdS nanoparticles on the CNT surface from an aqueous solution containing the Cd^II salt, thiourea, and ammonia was developed. The dependences of the size of particles formed on the CNT on the temperature of the solution and the duration of precipitation were observed. The degree of imperfection of the CNT surface exerts a substantial effect on the density of the precipitated CdS particles.     

Effect of iron nanoparticles in the films of composite materials and carbon nanotubes on the angular dependence of X-ray emission

The angular dependences of X-ray emission were measured for a series of polymer film samples with different concentration of finely dispersed iron. X-ray fluorescence maximum was found to shift toward higher angles with increasing the iron concentration in a sample. The form of angular dependences of X-ray emission was calculated taking into account the particle absorption coefficients in a composite material for incident and emitted radiation. The experimental and theoretical dependences were compared to estimate the content of nanoparticles in the polymer composite and iron nanoparticles in the samples of oriented carbon nanotubes.     

Neutrino Burst Monitoring in Our Galaxy

Journal of Experimental and Theoretical Physics - Baksan underground scintillation telescope (BUST) operates under the program of neutrino burst search since the middle of 1980. We report the...     

The search for ultrashort bursts of cosmic ray intensity on the Andyrchi air shower array

A new data acquisition system that makes it possible to measure the count rate of each detector of the Andyrchi air shower array every millisecond is described. This new detection system allows us to search for ultrashort bursts of cosmic ray intensity when operating the array in the single-component detection mode. The method of data acquisition and analysis is discussed.     

The Carpet-3 experiment to search for diffuse gamma rays with energies of more than 100 TeV

An experiment for measuring the flux of cosmic diffuse gamma rays with energies above 100 TeV (the Carpet-3 air shower array) is now being prepared at the Baksan Neutrino Observatory, Institute for Nuclear Research, Russian Academy of Sciences. The preparations entail a substantial increase of the areas of both the muon detector and the surface air shower array. The experiment’s sensitivity to showers generated by primary gamma rays is estimated for different configurations of the array. In addition, preliminary estimates of the upper limit on the flux of diffuse gamma rays with energies higher than 1.3 PeV, derived using experimental data from the old Carpet-2 array, are presented for a net exposure time of 9.2 years.