Персона:
Григоренко, Леонид Валентинович

Организационные подразделения

Организационная единица

Институт лазерных и плазменных технологий

Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.

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Григоренко

Имя

Леонид Валентинович

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Теперь показываю 1 - 10 из 23

Только метаданные
Evidence for the First Excited State of H 7
(2020) Bezbakh, A. A.; Chudoba, V.; Krupko, S. A.; Biare, D.; Belogurov, S. G.; Grigorenko, L. V.; Белогуров, Сергей Геннадьевич; Григоренко, Леонид Валентинович
© 2020 American Physical Society.The H7 system was populated in the H2(He8,He3)H7 reaction with a 26 AMeV He8 beam. The H7 missing mass energy spectrum, the H3 energy and angular distributions in the H7 decay frame were reconstructed. The H7 missing mass spectrum shows a peak, which can be interpreted either as unresolved 5/2+ and 3/2+ doublet or one of these states at 6.5(5) MeV. The data also provide indications of the 1/2+ ground state of H7 located at 1.8(5) MeV with quite a low population cross section of ∼25 μb/sr within angular range θc.m.≃(17°-27°).
Только метаданные
High-precision studies of the soft dipole mode in two-neutron halo nuclei: The He-6 case
(2020) Grigorenko, L. V.; Shulgina, N. B.; Zhukov, M. V.; Григоренко, Леонид Валентинович
The soft dipole E1 strength function is calculated for the transition from the He-6 0(+) ground state to the 1(-) continuum He-4+n + n. The calculations were performed within the hyperspherical harmonics formalism. The sensitivity of the results to the He-6 ground-state structure and to final-state interactions, are analyzed. The large-basis calculations show the reliably converged results for soft dipole strength function and for momentum correlations of the He-6 -> He-4+n + n dissociation products. Transition mechanisms are analyzed based on the momentum correlations. The comparison with experimental data is provided.
Только метаданные
Detection of the Low Energy Recoil 3He in the Reaction 2H(8He,3He)7H
(2020) Muzalevskii, I. A.; Chudoba, V.; Bezbakh, A. A.; Biare, D.; Belogurov, S. G.; Grigorenko, L. V.; Белогуров, Сергей Геннадьевич; Григоренко, Леонид Валентинович
© 2020, Allerton Press, Inc.Abstract: Investigation of the 7H-system in the experiment conducted at the fragment separator ACCULINNA-2 in the 8He(2H,3He)7H reaction requires to detect the recoil 3He ions with energy down to 6 MeV. For this purpose two ∆ E-E particle telescopes are used, with each telescope having in front a thin (20-μm) Si strip detector (∆E-SSD). The maps of thickness heterogeneity of the thin detectors were determined by measuring the energy losses of the 226Ra α-particles. The adopted thickness normalization method provides a good identification of the 3He nuclei being recorded in the presence of a high 4He background. Two approaches were used for calculating the energy losses of the identified 3He and 4He reaction ejectiles and reconstructing their energy values available at the exit from the deuterium target. The developed techniques were applied for the 7H missing-mass reconstruction.
Только метаданные
Status of the new fragment separator ACCULINNA-2 and first experiments
(2020) Kaminski, G.; Zalewski, B.; Belogurov, S. G.; Bezbakh, A. A.; Grigorenko, L. V.; Григоренко, Леонид Валентинович
© 2019 Elsevier B.V. The start of operation of a new separator ACCULINNA-2 makes an important upgrade for the Radioactive-Ion Beam (RIB) research done at the Flerov Laboratory of Nuclear Reactions (FLNR, JINR). Test results indicate that the separator meets the project specifications. Intensities obtained for the 6,8 He, 9,11 Li, 12 Be RIBs are 15 times higher in comparison with the results achieved at the old separator ACCULINNA. An overview of the design, construction and commissioning studies of the ACCULINNA-2 separator is presented. The separator will be equipped with some key facilities: a cryogenic tritium target, zero degree spectrometer following the physical target bombarded by the RIBs, and with a neutron detector array, and the Time Projection Chamber (TPC). This opens a wide range of experimental possibilities. Overview is presented on the two first experiments devoted to the study of d + 6 He elastic scattering and search for a 7 H low-lying resonance state populated in the 2 H( 8 He, 3 He) 7 H reaction.
Только метаданные
Validity of Quasi-classical Approaches to True Three-Body Decays
(2020) Sukhareva, O. M.; Kostyleva, D. A.; Zhukov, M. V.; Grigorenko, L. V.; Григоренко, Леонид Валентинович
© Springer Nature Switzerland AG 2020.Within the hyperspherical harmonics (HH) method the three-body problem is reduced to a motion of one effective particle in a “strongly deformed” field, which is described in the coupled-channel formalism. This method is well suited to studies of so-called true three-body decays. The reduction of the hyperspherical equations set to a single-channel approximation provides the basis of standard quasi-classical (QC) expression for width evaluation. We demonstrate that by itself the quasi-classical approach is quite precise in application to typical three-body effective potentials. However, the reduction to a single channel leads to a significant overestimation of the width.
Только метаданные
Towards the Limits of Existence of Nuclear Structure: Observation and First Spectroscopy of the Isotope K-31 by Measuring Its Three-Proton Decay
(2019) Kostyleva, D.; Mukha, I.; Acosta, L.; Casarejos, E.; Grigorenko, L. V.; Григоренко, Леонид Валентинович
The most remote isotope from the proton dripline (by 4 atomic mass units) has been observed: K-31. It is unbound with respect to three-proton (3p) emission, and its decays have been detected in flight by measuring the trajectories of all decay products using microstrip detectors. The 3p emission processes have been studied by the means of angular correlations of S-28 + 3p and the respective decay vertices. The energies of the previously unknown ground and excited states of K-31 have been determined. This provides its 3p separation energy value S-3p of -4.6(2) MeV. Upper half-life limits of 10 ps of the observed K-31 states have been derived from distributions of the measured decay vertices.
Только метаданные
Detailed Study of External Correlations in the Low-Energy Spectrum of Beryllium-6
(2019) Chudoba, V.; Fomichev, A. S.; Bezbakh, A. A.; Egorova, I. A.; Grigorenko, L. V.; Григоренко, Леонид Валентинович
© 2019, Allerton Press, Inc.Abstract: Three-body continuum p-p-α for the charge exchange reaction 1H(6Li,6Be)n is studied in detail. The data are obtained with a high volume of statistics (approximately 4.7 million events), making it possible to analyze three-particle correlations. Detailed information about the structure of 6Ве and the reaction is obtained as a result.
Только метаданные
Pauli-principle Driven Correlations in Four-neutron Nuclear Decays
(2019) Sharov, P. G.; Ismailova, A. N.; Zhukov, M. V.; Grigorenko, L. V.; Григоренко, Леонид Валентинович
© 2019, Pleiades Publishing, Inc.Mechanism of simultaneous non-sequential four-neutron (4n) emission (or “true” 4n-decay) has been considered in phenomenological five-body approach. This approach is analogous to the model of the direct decay to the continuum often applied to 2n-and 2p-decays. It is demonstrated that 4n-decay fragments should have specific energy and angular correlations reflecting strong spatial correlations of “valence” nucleons orbiting in their 4n-precursors. Due to the Pauli exclusion principle, the valence neutrons are pushed to the symmetry-allowed configurations in the 4n-precursor structure, which causes a “Pauli focusing” effect. Prospects of the observation of the Pauli focusing have been considered for the 4n-precursors 7Hand 28 O. Fingerprints of their nuclear structure or/and decay dynamics are predicted.
Только метаданные
The First Experiments with the New ACCULINNA-2 Fragment Separator
(2019) Fomichev, A. S.; Bezbakh, A. A.; Wolski, R.; Gazeeva, E. M.; Belogurov, S. G.; Grigorenko, L. V.; Белогуров, Сергей Геннадьевич; Григоренко, Леонид Валентинович
© 2019, Allerton Press, Inc.Abstract: Characteristics of a new separator of radioactive ion beams (RIBs) are described. It was recently commissioned at the Flerov Laboratory of Nuclear Reactions (FLNR JINR) and is in operation at the primary beam line of the U-400M heavy ion cyclotron providing RIBs in energy range of 10–50 MeV/nucleon. Preliminary results obtained in the first experiments performed with this separator in 2018 are presented. A medium-term program of scientific research is discussed.
Только метаданные
Scientific program of DERICA-prospective accelerator and storage ring facility for radioactive ion beam research
(2019) Grigorenko, L. V.; Sharkov, B. Y.; Fomichev, A. S.; Barabanov, A. L.; Barth, W.; Polozov, S. M.; Yaramyshev, S.; Григоренко, Леонид Валентинович; Полозов, Сергей Маркович
Studies of radioactive ions (RIs) are the most thriving field of low-energy nuclear physics. In this paper, the concept and the scientific agenda of the prospective accelerator and storage ring facility for RI beam (RIB) research are proposed for a large-scale international project based at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research. The motivation for the new facility is discussed and its characteristics are briefly presented and shown to be comparable to those of advanced world centers, the so-called "RIB factories". In the project, the emphasis is made on studies with short-lived RIBs in storage rings. Aunique feature of the project is the possibility of studying electron-RI interactions in a collider experiment to determine the fundamental properties of nuclear matter, in particular, electromagnetic form factors of exotic nuclei.