Персона: Леонов, Алексей Анатольевич
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Институт ядерной физики и технологий
Цель ИЯФиТ и стратегия развития - создание и развитие научно-образовательного центра мирового уровня в области ядерной физики и технологий, радиационного материаловедения, физики элементарных частиц, астрофизики и космофизики.
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- ПубликацияТолько метаданныеThe Future Space-Based GAMMA-400 Gamma-Ray Telescope for Studying Gamma and Cosmic Rays(2019) Topchiev, N. P.; Bakaldin, A. V.; Gusakov, Y. V.; Dalkarov, O. D.; Galper, A. M.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Leonov, A. A.; Naumov, P. Y.; Runtso, M. F.; Kheymits, M. D.; Chernysheva, I. V.; Yurkin, Y. T.; Архангельская, Ирина Владимировна; Архангельский, Андрей Игоревич; Леонов, Алексей Анатольевич; Наумов, Петр Юрьевич; Хеймиц, Максим Дмитриевич; Чернышева, Ирина Вячеславовна; Юркин, Юрий Тихонович© 2019, Allerton Press, Inc.Abstract: The future space-based γ-ray telescope GAMMA-400 will be installed on the Navigator platform of the Russian astrophysical observatory. A highly elliptical orbit will allow prolonged (~100 days) continuous observations of many regions of the celestial sphere for 7–10 years. GAMMA-400 will measure fluxes of γ‑ray emission in the energy range of ~20 MeV to several TeV and electrons + positrons to ~20 TeV. The γ-ray telescope will have excellent separation of γ-ray emissions against the background of cosmic rays and electrons + positrons from protons, along with unprecedented angular (~0.01° at Eγ = 100 GeV) and energy (~1% at Eγ = 100 GeV) resolutions 5–10 times better than for the Fermi-LAT and ground-based γ-ray telescopes. GAMMA-400 observations will provide fundamentally new data on discrete sources and spectra of γ-ray emissions and electrons + positrons.
- ПубликацияТолько метаданныеA System for Generating the Trigger Signals of the Spaceborne GAMMA-400 Telescope(2019) Bakaldin, A. V.; Gusakov, Y. V.; Dalkarov, O. D.; Egorov, A. E.; Arkhangelskiy, A. I.; Galper, A. M.; Arkhangelskaja, I. V.; Leonov, A. A.; Runtso, M. F.; Kheymits, M. D.; Chasovikov, E. N.; Chernysheva, I. V.; Yurkin, Y. T.; Архангельский, Андрей Игоревич; Архангельская, Ирина Владимировна; Леонов, Алексей Анатольевич; Хеймиц, Максим Дмитриевич; Часовиков, Евгений Николаевич; Чернышева, Ирина Вячеславовна; Юркин, Юрий Тихонович© 2019, Allerton Press, Inc.Abstract: The GAMMA-400 space project is one of the new generation of space observatories designed to search for signs of dark matter in the cosmic gamma emission, and to measure the characteristics of diffuse gamma-ray emission and gamma-rays from the Sun during periods of solar activity; gamma-ray bursts; extended and point gamma-ray sources; and electron, positron, and cosmic-ray nuclei fluxes with energies in the TeV ranges. The GAMMA-400 γ-ray telescope constitutes the core of the scientific instrumentation. The nature of the intended experiments imposes stringent requirements on the gamma telescope’s system of trigger signal formation, now being developed using the state-of-the-art logic devices and fast data links. The design concept of the system is discussed, along with the chosen engineering solutions and some experimental results obtained during the operation of the system prototype using a positron beam with energies of 100–300 MeV from the PAKHRA S-25R synchrotron at the Lebedev Physical Institute.
- ПубликацияТолько метаданныеGalactic Cosmic Ray Electrons and Positrons over a Decade of Observations in the PAMELA Experiment(2019) Adriani, O.; Bazilevskaya, G. A.; Barbarino, G. C.; Bellotti, R.; Mikhailov, V. V.; Voronov, S. A.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S. A.; Leonov, A. А.; Mayorov, A. G.; Malakhov, V. V.; Runtso, M. F.; Spillantini, P.; Yurkin, Y. T.; Михайлов, Владимир Владимирович; Воронов, Сергей Александрович; Колдобский, Сергей Александрович; Леонов, Алексей Анатольевич; Майоров, Андрей Георгиевич; Малахов, Виталий Валерьевич; Юркин, Юрий Тихонович© 2019, Allerton Press, Inc.Abstract: The PAMELA magnetic spectrometer was launched onboard the Resurs-DK1 satellite into a near-polar Earth orbit with an altitude of 350–600 km, in order to study fluxes of cosmic ray particles and antiparticles in the wide energy range of ~80 MeV to hundreds of GeV. The results from observations of electron and positron fluxes in 2006–2016 are presented.
- ПубликацияТолько метаданныеGammas and Charged Particles Identification in Lateral and Additional Apertures of GAMMA-400(2019) Bakaldin, A. V.; Dalkarov, O. D.; Egorov, A. E.; Gusakov, Y. V.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Galper, A. M.; Chernysheva, I. V.; Chasovikov, E. N.; Kheymits, M. D.; Leonov, A. A.; Runtso, M. F.; Yurkin, Y. T.; Архангельская, Ирина Владимировна; Архангельский, Андрей Игоревич; Чернышева, Ирина Вячеславовна; Часовиков, Евгений Николаевич; Хеймиц, Максим Дмитриевич; Леонов, Алексей Анатольевич; Юркин, Юрий Тихонович© 2019, Pleiades Publishing, Ltd.The GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be a new generation satellite gamma-observatory. The gamma-ray telescope GAMMA-400 consists of the anticoincidence system (top and lateral sections—ACtop and AClat), the converter-tracker (C), the time-of-flight system TOF (two sections S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the scintillation detectors of the calorimeter (S3 and S4) and lateral anticoincidence detectors of the calorimeter LD. Two apertures used for observation of transient events do not require the best angular resolution as for the gamma-ray bursts and solar flares from both upper and lateral directions. Additional aperture allows the particle registering from upper direction, which do not interact with converter-tracker and do not form a TOF signal. The lateral aperture allows registering of γ-quanta in perpendicular direction with respect to main axis of GAMMA-400 due to CC2, LD, S3, and S4. The thickness of CC2 in this direction is ∼44 X0 and this allows detection of gammas, electrons and positrons with energies up to 10 TeV. The results of calculation of the fractal dimension of temporal profiles of additional aperture prototype of GAMMA-400 during its calibration using secondary positron beam of the synchrotron C-25P “PAKHRA” of Lebedev Physical Institute confirm the absence of any correlation between the AC and CC1 characteristics and correspondence of additional aperture background to Poisson statistics or Erlang one with shape parameter up to 10.
- ПубликацияТолько метаданныеCosmic ray electron and positron spectrum with the PAMELA experiment(2019) Adriani, O.; Barbarino, G.; Bazilevskaya, G. A.; Bellotti, R.; Mikhailov, V. V.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S. A.; Leonov, A. A.; Malakhov, V. V.; Mayorov, A. G.; Spillantini, P.; Voronov, S. A.; Yurkin, Yu. T.; Михайлов, Владимир Владимирович; Колдобский, Сергей Александрович; Леонов, Алексей Анатольевич; Малахов, Виталий Валерьевич; Майоров, Андрей Георгиевич; Воронов, Сергей Александрович; Юркин, Юрий Тихонович© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).The PAMELA magnetic spectrometer, located on board the Resurs-DK1 satellite on Earth polar orbit with altitude of 350-600 km, measured the fluxes of cosmic ray particles and antiparticles in a wide energy range from 50 MeV to several TeVs. In this paper new results on the "all-electron" (sum electrons and positrons) spectrum are presented. New improved analysis on the full data set from 2006 to 2016 allows a significant increase in statistic compared to previously published results and an extension of energy interval up to 1 TeV.
- ПубликацияТолько метаданныеCapabilities of the Gamma-400 Gamma-ray Telescope for Observation of Electrons and Positrons in the TeV Energy Range(2019) Topchiev, N. P.; Bakaldin, A. V.; Suchkov, S. I.; Leonov, A. A.; Galper, A. M.; Kheymits, M. D.; Mikhailova, A. V.; Mikhailov, V. V.; Леонов, Алексей Анатольевич; Хеймиц, Максим Дмитриевич; Михайлова, Анна Владимировна; Михайлов, Владимир Владимирович© 2019, Pleiades Publishing, Ltd.The space-based GAMMA-400 gamma-ray telescope will measure the fluxes of gamma rays in the energy range from ∼20 MeV to several TeV and cosmic-ray electrons and positrons in the energy range from several GeV to several TeV to investigate the origin of gamma-ray sources, sources and propagation of the Galactic cosmic rays and signatures of dark matter. The instrument consists of an anticoincidence system, a converter-tracker (thickness one radiation length, 1 X0), a time-of-flight system, an imaging calorimeter (2 X0) with tracker, a top shower scintillator detector, an electromagnetic calorimeter from CsI(Tl) crystals (16 X0) with four lateral scintillation detectors and a bottom shower scintillator detector. In this paper, the capability of the GAMMA-400 gamma-ray telescope for electron and positron measurements is analyzed. The bulk of cosmic rays are protons, whereas the contribution of the leptonic component to the total flux is ∼10−3 at high energy. The special methods for Monte Carlo simulations are proposed to distinguish electrons and positrons from proton background in the GAMMA-400 gamma-ray telescope. The contribution to the proton rejection from each detector system of the instrument is studied separately. The use of the combined information from all detectors allows us to reach a proton rejection of up to ∼1 × 104.
- ПубликацияТолько метаданныеMultiple Coulomb scattering method to reconstruct low-energy gamma–ray direction in the GAMMA-400 space-based gamma–ray telescope(2019) Topchiev, N. P.; Bakaldin, A. V.; Dalkarov, O. D.; Egorov, A. E.; Leonov, A. А.; Galper, A. M.; Dzhivelikyan, E. A.; Kheymits, M. D.; Mikhailov, V. V.; Yurkin, Y. T.; Леонов, Алексей Анатольевич; Хеймиц, Максим Дмитриевич; Михайлов, Владимир Владимирович; Юркин, Юрий Тихонович© 2019 COSPAR The GAMMA-400 currently developing space-based gamma-ray telescope is designed to measure the gamma-ray fluxes in the energy range from ∼20 MeV to several TeV in the highly elliptic orbit (without shadowing the telescope by the Earth) continuously for a long time. The physical characteristics of the GAMMA-400 gamma-ray telescope, especially the angular and energy resolutions (at 100-GeV gamma rays they are ∼0.01° and ∼1%, respectively), allow us to consider this space-based experiment as the next step in the development of extraterrestrial high-energy gamma-ray astronomy. In this paper, a method to improve the reconstruction accuracy of incident angle for low-energy gamma rays in the GAMMA-400 space-based gamma-ray telescope is presented. The special analysis of topology of pair-conversion events in thin layers of converter was performed. Applying the energy dependence of multiple Coulomb scattering for pair components, it is possible to estimate the energies for each particle, and to use these energies as weight in the angle reconstruction procedure. To identify the unique track in each projection the imaginary curvature method is applied. It allows us to obtain significantly better angular resolution in comparison with other methods applied in current space-based experiments. When using this method for 50-MeV gamma rays the GAMMA-400 gamma-ray telescope angular resolution is about 4°.
- ПубликацияОткрытый доступNew method of high-energy gamma ray direction reconstruction in multilayered converters(2019) Bakaldin, A. V.; Gusakov, Y. V.; Dalkarov, O. D.; Egorov, A. E.; Kheymits, M. D.; Galper, A. M.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Djivelikyan, E. A.; Leonov, A. А.; Naumov, P. Y.; Runtso, M. F.; Yurkin, Y. T.; Zverev, V. G.; Хеймиц, Максим Дмитриевич; Архангельская, Ирина Владимировна; Архангельский, Андрей Игоревич; Леонов, Алексей Анатольевич; Наумов, Петр Юрьевич; Юркин, Юрий Тихонович© Published under licence by IOP Publishing Ltd.A new method of high-energy gamma ray incident direction reconstruction is developed for gamma-ray detectors with multilayered converters. The method uses data from converter and, if available, from position-sensitive calorimeter to reconstruct an electromagnetic cascade axis and to determine the incident direction of a primary gamma. For the first time to find point of intersection of gamma direction line with convertor plane, median of energy deposit in sensitive plane of convertor is used. Applied, for example, to the GAMMA-400 space-based gamma-ray telescope this method allowed to achieve the angular resolution ∼0.01° at gamma-ray energy of 100 GeV, being much better than accuracy of the past and present space- A nd ground-based experiments. In the algorithm presented, a balance between the angular resolution and the effective area can be found to meet a scientific goal of an experiment.
- ПубликацияОткрытый доступTime dependence of the helium flux measured by PAMELA(2019) Marcelli, N.; Adriani, O.; Barbarino, G. C.; Bazilevskaya, G. A.; Galper, A. M.; Karelin, A. V.; Koldashov, S. V.; Koldobskiy, S.; Leonov, A.; Malakhov, V.; Mayorov, A. G.; Mikhailov, V. V.; Voronov, S. A.; Yurkin, Y. T.; Колдобский, Сергей Александрович; Леонов, Алексей Анатольевич; Малахов, Виталий Валерьевич; Майоров, Андрей Георгиевич; Михайлов, Владимир Владимирович; Воронов, Сергей Александрович; Юркин, Юрий ТихоновичPrecision measurements of the Z = 2 component in cosmic radiation provide crucial information about the origin and propagation of the second most abundant cosmic ray species in the Galaxy (9% of the total). These measurements, acquired with the PAMELA space experiment orbiting Earth, allow to study solar modulation in details. Helium modulation is compared to the modulation of protons to study possible dependencies on charge and mass. The time dependence of helium fluxes on a monthly basis measured by PAMELA has been studied for the period between July 2006 to January 2016 in the energy range from 800 MeV/n to similar to 20 GeV/n.
- ПубликацияОткрытый доступGAMMA-400 experiment: Perspectives of observation of the discrete astrophysical gamma-ray sources in the Milky Way disk(2019) Bakaldin, A. V.; Suchkov, S. I.; Topchiev, N. P.; Galper, A. M.; Leonov, A. А.; Леонов, Алексей Анатольевич© Published under licence by IOP Publishing Ltd. The GAMMA-400 space experiment is aimed for the study of gamma rays in the energy range from ∼20 MeV up to several TeV. The observations will carry out with GAMMA-400 gamma-ray telescope installed onboard the Russian space observatory. GAMMA-400 has unique angular and energy resolutions for gamma rays with energy more than few GeV, which are significantly better than the Fermi-LAT ones. The orbit of the GAMMA-400 space observatory (near-Earth, circular with altitude about 200000 km) will be without the occultation by the Earth and outside the radiation belt. Thus it will be possible to carry out the continuous long-term observations of gamma-ray sources on the sky. In this work we present the expected statistics of gamma quanta that can be collected with GAMMA-400 from known discrete astrophysical gamma-ray sources in the disk of our galaxy during observations in orbit. 3FGL and 3FHL catalogs of discrete gamma-ray sources obtained in the Fermi experiment were used to calculate the number of gammas. It is shown that the accumulated statistics will allow us to carry out detailed investigation of characteristics (such as spatial distribution, energy spectrum, variability) of discrete gamma-ray sources in the Milky Way disk.