Experimental data for the tensor analyzing power T_20 in the γ d →π ^- p p reaction were obtained in the photon energy range from 400 to 650 MeV, with the proton momenta in the laboratory system exceeding 400 MeV/c. The data were taken at the Budker Institute of Nuclear Physics using an internal tensor-polarized gas deuterium target and tagged photons. The incident photons in the photoproduction reaction γ d →π ^- p p correspond to quasi-real virtual photons generated via electron scattering in the electroproduction process e d → eπ ^- p p at small four-momentum transfer. The two final protons were detected in coincidence. The tensor analyzing power T_20 was extracted from the yield asymmetry observed upon reversal of the sign of the deuteron tensor polarization. The experimental results are compared with statistical simulations performed within the framework of a spectator model that includes interaction between the final particles. The comparison demonstrates that accounting for the interaction effects significantly improves the agreement with the data.

New measurements of the T20 component of tensor analyzing power in the reaction γd→ppπ− for photon energies 400−700 MeV are presented. The experiment was carried out on an internal tensor-polarized gas deuterium target of the VEPP-3 electron storage ring in 2023 with the use of tagged quasi-real photons and two-proton coincidence. For determination of T20, the asymmetry caused by a change of the sign of the tensor polarization of the deuteron target was measured. The new data are compared with the results of theoretical calculations based on the quasi-free approximation including πN and NN rescattering effects.

The experiment on photodisintegration of tensor polarized deuteron is in progress. It is carried out at VEPP-3 storage ring using the internal polarized gas target technique. The component T20 of the tensor analyzing power is obtained by measuring the target polarization asymmetry in the photon energy range up to 1600MeV. The energy of photons is defined by the system that tags nearly real photons developed at the Budker Institute of Nuclear Physics (BINP).

Проведено исследование характеристики вторичного рентгеновского излучения, генерируемого в процессе работы стерилизатора на основе сильноточного импульсно-периодического ускорителя электронов СИНУС-320. Энергия ускоренных электронов составляет 500 кэВ. В связи с этим возникает необходимость радиационной защиты при эксплуатации установки, что, в свою очередь, приводит к важности изучения энергетического спектра и мощности дозы вторичного рентгеновского излучения. Исследования были проведены методом статистического моделирования с использованием программного пакета GEANT4. The work presents a study of the parameters of secondary X-ray radiation generated during the operation of a sterilization setup based on a high-current pulse-periodic electron accelerator SINUS-320. The energy of accelerated electrons equals 500 keV. Therefore, the issues of radiation protection during operation of the installation is highly topical, that leads to the importance of studying the energy spectrum and dose rate of secondary X-ray radiation. The studies were carried out by statistical simulation via GEANT4 toolkit.

New results have been presented for the T 20 component of the tensor analyzing power of the γ d → pp π – reaction measured in the photon energy range from 300 to 600 MeV. The data have been obtained from the statistical sample collected at the VEPP-3 accelerator in 2021. The T 20 component has been separated using the asymmetry of the reaction yield, which is due to change in the sign of the tensor polarization of the deuterium target. The experimental data have been compared to the simulation within the spectator model including the interaction between particles in the final state.

In this paper, we present new experimental results for the tensor analyzing power T_20 of the reaction γ d→ pnπ^0 in the region of low proton energies. The results are presented in the photon energy range of 300 MeV

New results for the T20-component of the tensor-analyzing power of the incoherent negative pion photoproduction are presented. The experiment was performed for the electron beam energy of 800 MeV at the VEPP-3 storage ring in 2021. To extract the T20-component, we used asymmetry with respect to the change in the sign of the tensor polarization of the deuteron target. Identification of the reaction events was carried out by the detection of two protons in coincidence. Experimental data were compared with the results of statistical simulation, considering the interaction between the NN and πN subsystems in the final state of the reaction.

AbstractTensor analyzing-power components $$T_{20}$$ T 20 , $$T_{21}$$ T 21 , and $$T_{22}$$ T 22 for the reaction $$\gamma d\rightarrow np\pi ^0$$ γ d → n p π 0 have been studied for the first time in the photon energy range from 280 to 500 MeV. The data are extracted from the experimental statistics accumulated at the VEPP-3 storage ring in 2002–2003. The measured asymmetries are compared with the results of statistical simulations performed with the $$\gamma d\rightarrow np\pi ^0$$ γ d → n p π 0 amplitude from a spectator model, taking into account corrections for the final-state interaction. The comparison demonstrates quite good agreement between the experimental results and the theory.

Tensor analyzing-power components [Formula: see text], [Formula: see text], and [Formula: see text] for the reaction [Formula: see text] have been studied for the first time in the photon energy range from 280 to 500 MeV. The data are extracted from the experimental statistics accumulated at the VEPP-3 storage ring in 2002-2003. The measured asymmetries are compared with the results of statistical simulations performed with the [Formula: see text] amplitude from a spectator model, taking into account corrections for the final-state interaction. The comparison demonstrates quite good agreement between the experimental results and the theory.

Tensor analyzing-power components $$T_{20}$$ , $$T_{21}$$ , and $$T_{22}$$ for the reaction $$\gamma d\rightarrow np\pi ^0$$ have been studied for the first time in the photon energy range from 280 to 500 MeV. The data are extracted from the experimental statistics accumulated at the VEPP-3 storage ring in 2002–2003. The measured asymmetries are compared with the results of statistical simulations performed with the $$\gamma d\rightarrow np\pi ^0$$ amplitude from a spectator model, taking into account corrections for the final-state interaction. The comparison demonstrates quite good agreement between the experimental results and the theory.

Parasitic X-ray radiation for the backward wave oscillator SINUS-350 is investigated. Using the GEANT4 simulation toolkit we have made a model of this oscillator which allows calculating the radiation dose and energy spectrum around the accelerator. The results of these calculations have been compared with measurements for 2 s accelerator operation time. The obtained values of radiation doses at a distance of 1-2 m from the generator are in the range (10-300) mu Sv. These values significantly exceed the maximum permissible amount because the personal maximum permissible dose per year is 1000 mu Sv. Therefore, the question of how to achieve a significant reduction is very important. We have also calculated the energy spectrum of the X-rays for different places. The largest part of the spectrum is in the range 50-350 keV.

Tensor analyzing-power components T20, T21, and T22 for the reaction gamma d -> np pi 0 have been studied for the first time in the photon energy range from 280 to 500 MeV. The data are extracted from the experimental statistics accumulated at the VEPP-3 storage ring in 2002-2003. The measured asymmetries are compared with the results of statistical simulations performed with the gamma d -> np pi 0 amplitude from a spectator model, taking into account corrections for the final-state interaction. The comparison demonstrates quite good agreement between the experimental results and the theory.

In this paper, we present new experimental results for the tensor analyzing power T_20 of the reaction γ d→ pnπ^0 in the region of low proton energies. The results are presented in the photon energy range of 300 MeV<E_γ<600 MeV and the proton energy range of 10 MeV<E_p<40 MeV . The paper uses the experimental statistics accumulated at the VEPP-3 accelerator complex in 2013. To identify the events of the reaction γ d→ pnπ^0 , we used the registration of the proton and two γ -quanta from the decay π^0→ 2γ in coincidence. The experimental results were compared with the results of statistical simulation. To perform the statistical simulation, we used the unitary isobar model MAID 2007 for the elementary pion-nucleon photoproduction amplitude and took into account π N and NN rescattering in the final state of the reaction γ d→ pnπ^0 .

Tensor analyzing-power components T_20 , T_21 , and T_22 for the reaction γ d→ npπ ^0 have been studied for the first time in the photon energy range from 280 to 500 MeV. The data are extracted from the experimental statistics accumulated at the VEPP-3 storage ring in 2002–2003. The measured asymmetries are compared with the results of statistical simulations performed with the γ d→ npπ ^0 amplitude from a spectator model, taking into account corrections for the final-state interaction. The comparison demonstrates quite good agreement between the experimental results and the theory.

In this study, the Geant4 Monte Carlo toolkit was used to simulate radiation doses for a high-current repetitively pulsed electron accelerator. We have created a model that allows us to predict the distribution of radiation doses around an operating accelerator. The materials and geometry of the accelerator were in accordance with the design documentation. The values of radiation doses were obtained for different initial parameters of the electron beam. The values obtained are compared with the measurement results. Application of the developed model will make it possible to predict the distribution of the radiation dose around the accelerator. Note that the developed model is sensitive to the initial parameters of the electrons. This opens up a wide field of activity for studying the radiation effects around an operating accelerator, depending on the magnetic field of the solenoid, the cathode type, collector materials and slow wave structure. In the future it is planned to conduct a detailed study of the dependence of radiation doses on the geometry and composition of the collector, where most of the accelerated electrons are utilised. These studies will help to significantly reduce the radiation doses around the working accelerator.

The paper presents new results for the T20 analyzing power tensor component of the γd→pnπ0 reaction in the photon energy range of 300 MeV < Eγ < 500 MeV. The experimental statistics accumulated in 2013 at the VEPP-3 accelerator-storage complex using an internal tensor-polarized gaseous deuterium target has been used. The reaction events are identified by the coincidence registration of the proton and two gamma quanta from the neutral pion decay. To determine the T20 component, the asymmetry of the yields with respect to the change in the sign of the tensor polarization of the deuterium target is measured. Experimental results are compared with the theoretical calculations for the MAID 2007 model of the amplitude used as the elementary pion-nucleon photoproduction amplitude and contributions of pion-nucleon and nucleon-nucleon rescattering are taken into account.

Measured values of the tensor analyzing power T20 for the coherent photoproduction of a π0-meson on a deuteron are analyzed in the region of large momentum transfer. The incident photons of the photoproduction reaction γd→dπ0 are the quasi-real virtual photons arising from the electron scattering in the electroproduction reaction ed→edπ0. The kinematic region of large momentum transfer is of particular interest, as it corresponds to small inter-nucleon distances in the deuteron. In this case, the amplitude of the process under study is noticeably sensitive to both the deuteron wave function at small inter-nucleon distances and the various model uncertainties arising from the description of the process for large momentum transfer. A comparison shows a significant discrepancy between the experimental data and the predictions from a number of theoretical models.

This paper presents new results for the T-20-component of the tensor analyzing power of the reaction gamma d -> pr pi(0) in the photon energy range of 300 MeV < E gamma < 500 MeV. The experimental statistics accumulated in 2013 at the VEPP-3 accelerator-storage complex is used. The reaction events are identified by the coincidence registration of the proton and two gamma-quanta from the decay of the neutral pion. To determine the T-20-component, the asymmetry of the yields with respect to the change of sign of the tensor polarization of the deuterium target is measured. The experimental results are compared with the theoretical calculations in which the MAID 2007 model is used as the elementary pion-nucleon photoproduction amplitude and contributions from the pion-nucleon and nucleon-nucleon rescattering are taken into account.

This paper presents new results for the [Formula: see text]-component of the tensor analyzing power of the reaction [Formula: see text] in the photon energy range of [Formula: see text]. The experimental statistics accumulated in 2013 at the VEPP-3 accelerator-storage complex is used. The reaction events are identified by the coincidence registration of the proton and two [Formula: see text]-quanta from the decay of the neutral pion. To determine the [Formula: see text]-component, the asymmetry of the yields with respect to the change of sign of the tensor polarization of the deuterium target is measured. The experimental results are compared with the theoretical calculations in which the MAID 2007 model is used as the elementary pion–nucleon photoproduction amplitude and contributions from the pion–nucleon and nucleon–nucleon rescattering are taken into account.

In the present paper, we continue to study the two-dimensional soliton system that is composed of vortex and Q-ball components interacting with each other through an Abelian gauge field. This vortex-Q-ball system is electrically neutral as a whole, nevertheless it possesses a nonzero electric field. Moreover, the vortex-Q-ball system has a quantized magnetic flux and a nonzero angular momentum, and combines properties of topological and nontopological solitons. We investigate radially and azimuthally excited states of the vortex-Q-ball system along with the unexcited vortex-Q-ball system at different values of gauge coupling constants. We also ascertain the behaviour of the vortex-Q-ball system in several extreme regimes, including thin-wall and thick-wall regimes.