SearcharxivSearch

arXiv subjects

L. B. Bezrukov

Publications and source records attributed to L. B. Bezrukov.

12 recordsLinked to original sources

Low metallicity solar model finds the prove in Borexino data

The Borexino Collaboration interprets its data within the framework of Bulk Silicate Earth model and the model of the Sun with high metallicity. Other authors have given a different interpretation of the same data within the framework of Hydridic Earth model and low-metallicity Sun model. In order to understand what occasion takes place in Nature, the Borexino single events energy spectrum was numerically simulated using the Monte Carlo method for various assumptions about the processes that could exist in Nature. The existence of large potassium geo-antineutrino flux and its absence were considered. At the same time, the high or low metallicity of the Sun were included in simulations. A comparison of counting rates reconstruction from simulated data with the reconstruction ones from Borexino single events spectrum demonstrates that large potassium geo-antineutrino flux with low metallicity of the Sun is preferable and is realized in Nature.

hep-ex

The indication for $^{40}$K geo-antineutrino flux with Borexino phase-III data

We provide the indication of high flux of $^{40}$K geo-antineutrino and geo-neutrino ($^{40}$K-geo-($\barν + ν$)) with Borexino Phase III data. This result was obtained by introducing a new source of single events, namely $^{40}$K-geo-($\barν + ν$) scattering on electrons, in multivariate fit analysis of Borexino Phase III data. Simultaneously we obtained the count rates of events from $^7$Be, $pep$ and CNO solar neutrinos. These count rates are consistent with the prediction of the Low metallicity Sun model SSM B16-AGSS09. MC pseudo-experiments showed that the case of High metallicity Sun and absence of $^{40}$K-geo-($\barν + ν$) can not imitate the result of multivariate fit analysis of Borexino Phase III data with introducing $^{40}$K-geo-($\barν + ν$) events. We also provide arguments for the high abundance of potassium in the Earth.

hep-ex

Air ions induced aerosol sensing by eye-safe LIDAR

Low concentrations aerosols quantification is rather challenging for LIDAR instruments due to eye-safety restrictions so high energy pulses cannot be utilized to improve the sensitivity. Highly sensitive but eye-save LIDAR has been developed for the quantification of the water droplet aerosol which was induced by air ions. Few days sensing of aerosols in closed tunnel revealed a strong correlation between air optical transparency (LIDAR measurements) and concentrations of positive/negative ions (ion counter Sapphir 3-M). The correlation coefficient was observed to be almost unity for the air transparency signal and air ions unipolarity coefficient. High sensitivity of the water droplet aerosol quantification makes the developed eye-safe LIDAR a perspective instrument for space resolved measurements of the air ions distribution. Space and time resolved measurements of air ions exhalation can be a new instrument for tectonic activity study including new earthquake forecasting indicators search.

physics.ao-ph

On first detection of solar neutrinos from CNO cycle with Borexino

Borexino collaboration reported about first measurement of solar CNO-$ν$ interaction rate in Borexino detector. This result is consistent with Hydridic Earth model prediction about the contribution of $^{40}$K geo-antineutrino interactions in single Borexino events. The potassium abundance in the Earth in the range $1 ÷1.5$\% of the Earth mass could give the observed enhancement of counting rate above expected CNO-$ν$ counting rate. The Earth intrinsic heat flux must be in the range $200 ÷300$ TW for this potassium abundance. This value of the heat flux can explain the ocean heating observed by the project ARGO. We consider that Hydridic Earth model actually corresponds better to CNO-$ν$ Borexino results than Silicate Earth model.

hep-ex

On the contribution of the $^{40}$K geo-antineutrino to single Borexino events

We propose to include in the analysis of Borexino single event energy spectrum the scattering of $^{40}$K geo-antineutrinos by scintillator electrons. The Hydridic Earth model predicts the concentration of potassium in modern Earth from 1\% to 4\% of the Earth mass. We calculated contribution of $^{40}$K geo-antineutrino interactions in single Borexino events for these concentrations. This contribution is comparable to the contribution from the interaction of CNO neutrinos. We discuss the reasons for using the Hydridic Earth model.

hep-ex

Multichannel Data Acquisition System for Scintillation Detectors of the Emma Experiment

The multichannel data acquisition system is intended to be used in the EMMA experiment studying cosmic rays. The array will be in the Pihasalmi mine (central Finland) at a depth of about 85 m. The scintillator counters (SC-1) of the array are cast plastic scintillators with a wavelength of each SC-1 detector is 12.2{\times}12.2{\times}3.0 cm^3. 16 SC-1 detectors are placed in the metal case of 50.0{\times}50.0{\times}13.0 cm^3 dimension. Each case, called SC-16 detector, contains electronics of preliminary processing of signals and operating mode stabilization. The whole of the array will contain 96 detectors SC-16. It will make 1536 channels placed in three planes (48+24+24 detectors). The array will allow us to measure the time of flight of particles between SC-16 detectors and the coordinates of SC-1 fired detectors. This paper presents the function diagram of data acquisition system that includes electronic of detectors, the hodoscope pulse channels, the trigger block and VME blocks.

astro-ph.IM

Multi-pixel Geiger-mode avalanche photodiode and wavelength shifting fibre readout of plastic scintillator counters of the EMMA underground experiment

The results of a development of a scintillator counter with wavelength shifting (WLS) fibre and a multi-pixel Geiger-mode avalanche photodiode readout are presented. The photodiode has a metal-resistor-semiconductor layered structure and operates in the limited Geiger mode. The scintillator counter has been developed for the EMMA underground cosmic ray experiment.

physics.ins-det

On the level of background in underground muon measurements with plastic scintillator counters

In this short note we present results of background measurements carried out with a polystyrene based cast plastic 12.0x12.0x3.0 cm^3 size scintillator counter with a wavelength shifting fibre and a multi-pixel Geiger mode avalanche photodiode readout in the Baksan underground laboratory at a depth of 200 meters of water equivalent. The total counting rate of the scintillator counter measured at this depth and at a threshold corresponding to ~0.37 of a minimum ionizing particle is approximately 1.3 Hz.

physics.ins-det

Performances and stability of a 2.4 ton Gd organic liquid scintillator target for antineutrino detection

In this work we report the performances and the chemical and physical properties of a (2 x 1.2) ton organic liquid scintillator target doped with Gd up to ~0.1%, and the results of a 2 year long stability survey. In particular we have monitored the amount of both Gd and primary fluor actually in solution, the optical and fluorescent properties of the Gd-doped liquid scintillator (GdLS) and its performances as a neutron detector, namely neutron capture efficiency and average capture time. The experimental survey is ongoing, the target being continuously monitored. After two years from the doping time the performances of the Gd-doped liquid scintillator do not show any hint of degradation and instability; this conclusion comes both from the laboratory measurements and from the "in-tank" measurements. This is the largest stable Gd-doped organic liquid scintillator target ever produced and continuously operated for a long period.

physics.ins-det

Fast simulation of the Cherenkov light from showers

A method for fast simulation of the Cherenkov light generated by electromagnetic showers is described. The parametrization for the longitudinal profile is used and fluctuations and correlations of the parameters are taken into account in a consistent way. Our method dramatically reduces the CPU time and its results are in a rather good agreement with a full Monte Carlo simulation.

hep-ph

The Experimental Limits on Q-ball Flux with the Baikal Deep Underwater Array "Gyrlyanda"

Supersymmetric models allow for stable non-topological solitons, Q-balls, which can be produced in the early Universe and contribute to dark matter. Experimental signature of electrically neutral Q-balls is, in fact, the same as is expected for superheavy magnetic monopoles catalyzing baryon decay. Here we use the upper limits on monopole flux obtained with deep underwater Cherenkov array "Gyrlyanda" which operated in the Baikal lake in 1984-90 with 267 days of live time to obtain the limit on Q-ball flux. The last has been found to be equal to 3.9 x 10^{-16} cm^{-2} sr^{-1} s^{-1} (90% CL). This result is discussed and compared with other restrictions.

astro-ph