SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Ershov S. N.) "

Sökning: WFRF:(Ershov S. N.)

  • Resultat 1-24 av 24
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Aad, G, et al. (författare)
  • 2015
  • swepub:Mat__t
  •  
2.
  • Reifarth, R., et al. (författare)
  • Nuclear astrophysics with radioactive ions at FAIR
  • 2016
  • Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 665:1
  • Konferensbidrag (refereegranskat)abstract
    • The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process beta-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.
  •  
3.
  • Antonov, A. N., et al. (författare)
  • The electron-ion scattering experiment ELISe at the International Facility for Antiproton and Ion Research (FAIR)-A conceptual design study
  • 2011
  • Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002 .- 0167-5087. ; 637:1, s. 60-76
  • Tidskriftsartikel (refereegranskat)abstract
    • The electron-ion scattering experiment ELISe is part of the installations envisaged at the new experimental storage ring at the International Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany. It offers an unique opportunity to use electrons as probe in investigations of the structure of exotic nuclei. The conceptual design and the scientific challenges of ELISe are presented. (C) 2011 Elsevier B.V. All rights reserved.
  •  
4.
  • Grigorenko, L, et al. (författare)
  • Scientific program of DERICA-prospective accelerator and storage ring facility for radioactive ion beam research
  • 2019
  • Ingår i: Physics-Uspekhi. - 1468-4780 .- 1063-7869. ; 62:7, s. 675-690
  • Tidskriftsartikel (refereegranskat)abstract
    • 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. A unique 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.
  •  
5.
  • Fomichev, A. S., et al. (författare)
  • Long range plan with radioactive beams at Dubna
  • 2010
  • Ingår i: 3rd International Conference on Current Problems in Nuclear Physics and Atomic Energy, NPAE 2010; Kyiv; Ukraine; 7 June 2010 through 12 June 2010. ; , s. 64-69
  • Konferensbidrag (refereegranskat)abstract
    • A program for upgrade of existing radioactive ion beams facilities at Flerov Laboratory of Nuclear Reactions, JINR Dubna is presented. A project of a new in-flight fragment separator ACCULINNA-2 is proposed. It is expected the new instrument will be more universal and powerful than the existing nowadays. The beam intensity should be increased by factor 10-15, its optical quality greatly improved and the range of the accessible secondary radioactive beams broadened up to Z∼20. Main ion-optical characteristics, operating principles and a tentative plan for the project realization are included. An extensive research program based on local experiments made so far and international proposals for these equipments is discussed.
  •  
6.
  • Fomichev, A. S., et al. (författare)
  • Recent results related to excited states of 6Be and 10He
  • 2012
  • Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 38, s. Art. no. 15002-
  • Konferensbidrag (refereegranskat)abstract
    • The 1H(6Li,6Be)n charge-exchange reaction and the 3H(8He, p)10He two-neutron transfer reaction were recently carried out at the ACCULINNA fragment separator (FLNR, Dubna) to populate the ground and excited states of 6Be and 10He nuclei, respectively. The 6Be ET spectrum (ET is the 6Be energy above its 4He+p+p decay threshold) was obtained with high statistics and described by the well-known 0+ ground state of 6Be at ET = 1.37 MeV, the 2+ state at ET = 3.05 MeV and a broad structure extending from 4 to 16 MeV which could be interpreted as the isovector soft dipole mode associated with the 6Li ground state. In the 10He case the 0+ ground state was found at about 2.1(2) MeV (T ∼ 2 MeV) above the 8He+n+n breakup threshold. Angular correlations observed for 10He decay products show prominent interference patterns allowing to draw conclusions about the structure of low-energy excited states: 1- (E T ∼ 5 MeV) and 2+ (ET > 6 MeV).
  •  
7.
  • Fomichev, A. S., et al. (författare)
  • The Suggested New Fragment Separator ACCULINNA-2
  • 2010
  • Ingår i: Acta Physica Polonica, Series B.. - 1509-5770 .- 0587-4254. ; 41:2, s. 475-480
  • Tidskriftsartikel (refereegranskat)abstract
    • We present new project of fragment separator ACCULINNA-2 that is being planned to be constructed in Flerov Laboratory of Nuclear Reaction, JINR. The ACCULINNA-2 facility is not, intended to compete with the, new large in-flight RIB facilities. It, should complement the existing/constructed facilities in certain fields. Namely, ACCULINNA-2 should provide high intensity RIBs in the lowest energy range attainable for in-flight separators.
  •  
8.
  • Krupko, S. A., et al. (författare)
  • Fragment separator ACCULINNA-2
  • 2010
  • Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735407688 ; 1224, s. 516-521
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)
  •  
9.
  • Chudoba, V., et al. (författare)
  • Three-body correlations in direct reactions: Example of Be 6 populated in the (p,n) reaction
  • 2018
  • Ingår i: Physical Review C. - 2469-9993 .- 2469-9985. ; 98:5
  • Tidskriftsartikel (refereegranskat)abstract
    • The Be6 continuum states were populated in the charge-exchange reaction H1(Li6,Be6)n collecting very high statistics data (∼5×106 events) on the three-body α+p+p correlations. The Be6 excitation energy region below ∼3MeV is considered, where the data are dominated by contributions from the 0+ and 2+ states. It is demonstrated how the high-statistics few-body correlation data can be used to extract detailed information on the reaction mechanism. Such a derivation is based on the fact that highly spin-aligned states are typically populated in the direct reactions.
  •  
10.
  • Fomichev, A. S., et al. (författare)
  • Isovector soft dipole mode in Be-6
  • 2012
  • Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 708:1-2, s. 6-13
  • Tidskriftsartikel (refereegranskat)abstract
    • By using the H-1(Li-6,Be-6)n charge-exchange reaction, population of continuum states in Be-6 was observed up to E-T = 16 MeV, E-T being the Be-6 energy above its three-body decay threshold. In kinematically complete measurements performed by detecting alpha + p + p coincidences, an E-T spectrum of high statistics was obtained, containing approximately similar to 5 x 10(6) events. The spectrum provides detailed correlation information about the well-known 0(+) ground state of Be-6 at E-T = 1.37 MeV and its 2(+) state at E-T = 3.05 MeV. Moreover, a broad structure extending from 4 to 16 MeV was observed. It contains negative parity states populated by Delta L = 1 angular momentum transfer without other significant contributions. This structure can be interpreted as a novel phenomenon, i.e. the isovector soft dipole mode associated with the Li-6 ground state. The population of this mode in the charge-exchange reaction is a dominant phenomenon for this reaction, being responsible for about 60% of the cross-section obtained in the measured energy range.
  •  
11.
  • Fomichev, A. S., et al. (författare)
  • Status of the ACCULINNA-2 project at FLNR
  • 2012
  • Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 337:1, s. Art. no. 012025-
  • Konferensbidrag (refereegranskat)abstract
    • The project of a new and more powerful in-flight fragment separator ACCULINNA-2 at U-400M cyclotron in FLNR, JINR planned to build in addition to the existing separator ACCULINNA is presented. The new separator will provide high intensity RIBs in the lowest energy range (5÷50 MeV/nucleon) which is attainable for in-flight separators. The possibilities for the astrophysics studies at the proposed device are presented. ACCULINNA-2 separator is planned to be constructed in the years 2010-2015. The current status of the project is reported.
  •  
12.
  • Krupko, S. A., et al. (författare)
  • The status of new fragment separator ACCULINNA-2 project and the first day experiments
  • 2014
  • Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2101-6275 .- 2100-014X. ; 66
  • Konferensbidrag (refereegranskat)abstract
    • The new facility fragment separator ACCULINNA-2 will be put into operation at the beginning of 2015 in FLNR JINR. The new separator is destined to add considerably to the studies of drip-line nuclei performed with the use of variety of direct reactions known to be distinctive to the 15 - 50 MeV/amu exotic secondary RIBs. Intense beams provided by the U-400M cyclotron will ensure the achievement of this objective. In addition to the RIB separation accomplished by means of the dipole-wedge-dipole selection, the addition of a zero-degree dipole magnet setup is foreseen. A long (13 m) straight section will provide precise time-of-flight measurements. © Owned by the authors, published by EDP Sciences, 2014.
  •  
13.
  • Chudoba, V., et al. (författare)
  • Detailed Study of External Correlations in the Low-Energy Spectrum of Beryllium-6
  • 2019
  • Ingår i: Bulletin of the Russian Academy of Sciences: Physics. - 1062-8738 .- 1934-9432. ; 83:4, s. 392-398
  • Tidskriftsartikel (refereegranskat)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.
  •  
14.
  • Shulgina, N. B., et al. (författare)
  • Superhalo of C 22 reexamined
  • 2018
  • Ingår i: Physical Review C. - 2469-9985 .- 2469-9993. ; 97:6
  • Tidskriftsartikel (refereegranskat)abstract
    • An unusually large value of the C22 matter radius, extracted by Tanaka et al. [Phys. Rev. Lett. 104, 062701 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.062701] from measured reaction cross sections, attracted great attention of scientific community. Since that time, several experimental works related to the C22 nucleus have appeared in the literature. Some of the experimental data, measured with high accuracy, allow us to fix C22 structure more reliably. Two limiting models reproducing C22 nuclear structure within the three-body cluster approach, that allow us to describe all existing experimental data, are presented. The C22 ground state, continuum structure, and geometry are obtained. With fixed C22 wave function, the prediction for the soft dipole mode in C22, which is studied in the process of Coulomb fragmentation, is performed.
  •  
15.
  •  
16.
  • Danilin, B.V., et al. (författare)
  • Three-body continuum energy correlations in Borromean halo nuclei. III. Short-range external fields
  • 2007
  • Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 76, s. 064612-
  • Tidskriftsartikel (refereegranskat)abstract
    • Energy correlations in transition from the bound state to the three-body continuum of Borromean halo nuclei are considered. A core+n+n three-body cluster model which reproduces the experimentally known properties of 6He and 11Li has been used to study the low-lying resonances and soft modes. An analysis of the correlated responses in 6He shows that in the case of the narrow 2+ resonance the transition energy correlations are the same as in the intrinsic correlated structure in 3->3 scattering. They differ significantly for wide second 2+ and first 1+ resonances, and also for the soft dipole and monopole modes, where due to the transition operators, the intertwinning of the ground state and the three-body continuum plays a significant role.
  •  
17.
  • Ershov, S. N., et al. (författare)
  • Binding energy constraint on matter radius and soft dipole excitations of C-22
  • 2012
  • Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 86:3
  • Tidskriftsartikel (refereegranskat)abstract
    • An unusually large value of the C-22 matter radius has recently been extracted from measured reaction cross sections. The giant size can be explained by a very loose binding that is, however, not known experimentally yet. Within the three-body cluster model we have explored the sensitivity of the s-motion-dominated C-22 geometry to the two-neutron separation energy. A low energy of a few tens of keV is required to reach the alleged experimental lower value of the matter radius, while the experimental mean radius requires an extremely tiny binding. The dependence of the C-22 charge radius on the two-neutron separation energy is also presented. The soft dipole mode in C-22 is shown to be strongly affected by the loose binding and should be studied in the process of Coulomb fragmentation.
  •  
18.
  • Ershov, S. N., et al. (författare)
  • Cluster model with core excitations. The Be-11 example
  • 2014
  • Ingår i: Physics of Atomic Nuclei. - : Pleiades Publishing Ltd. - 1562-692X .- 1063-7788. ; 77:8, s. 989-998
  • Tidskriftsartikel (refereegranskat)abstract
    • Bound states and low-lying resonances of the Be-11 one-neutron halo nucleus have been calculated within a two-body cluster model with core excitation. The lowest Be-10 core excited 2(+) state was considered as a quadrupole vibration. Shallow potentials were applied for neutron-core interaction, preventing motion in Pauli forbidden orbits. A good description of available experimental data including dipole excitations of Be-11 was obtained. For the bound 1/2(-) excited state the wave-function component gives the dominant contribution to the structure, which differs from results obtained in cluster models with deep potentials.
  •  
19.
  • Ershov, S. N., et al. (författare)
  • Halo formation and breakup: lessons and open questions
  • 2010
  • Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 37:6
  • Tidskriftsartikel (refereegranskat)abstract
    • A quarter of a century's concerted international work in halo physics has resulted in an extended nuclear paradigm encompassing the limits of existence of cold nuclei and also structures beyond-continuum structures of open (nuclear) quantum systems. Realistic working models, based on cluster constituents, have sprung out of the very nature of halo phenomena, in particular from the three-body Borromean property of two-neutron halos, the lack of low-lying binary breakup channels. This has provided transparency and possibility for insight into new quantum behaviour, also in continua beyond driplines-a focus of this status assessment. Breakup spectra and progressively exclusive correlation cross sections can be computed and show, where relevant data exist, not only that general agreement is encouraging but also that some exclusive observables exhibit significant disagreement that has to be clarified. Progress in studies of two-proton emitters has provided another pathway beyond driplines, where again few-body theory appears promising.
  •  
20.
  • Ershov, S. N., et al. (författare)
  • Modified variable phase method for the solution of coupled radial Schrodinger equations
  • 2011
  • Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 84:6
  • Tidskriftsartikel (refereegranskat)abstract
    • A modified variable phase method for the numerical solution of coupled radial Schrodinger equations, which maintains linear independence for different sets of solution vectors, is suggested. The modification involves rearrangement of coupled equations to avoid the usual numerical instabilities associated with components of the wave function in their classically forbidden regions. The modified method is applied to nuclear structure calculations of halo nuclei within the hyperspherical harmonics approach.
  •  
21.
  • Ershov, S. N., et al. (författare)
  • New method for solution of coupled radial Schrodinger equations: application to the Borromean two-neutron halo nucleus C-22
  • 2014
  • Ingår i: Physics of Atomic Nuclei. - : Pleiades Publishing Ltd. - 1562-692X .- 1063-7788. ; 77:3, s. 374-383
  • Tidskriftsartikel (refereegranskat)abstract
    • A generalized Prufer transformation within the framework of the modified variable phase method has been used for numerical solution of coupled radial Schrodinger equations at negative energies. The method has been applied to calculations of the Borromean two-neutron halo nucleus C-22, for which an unusually large value of the matter radius has recently been extracted from measured reaction cross sections. The giant size can only be explained by an extremely loose binding that is, however, not yet known experimentally. Within the three-body cluster model we have explored the sensitivity of the C-22 matter and charge radii and soft dipole mode excitations to the two-neutron separation energy.
  •  
22.
  • Ershov, S. N., et al. (författare)
  • Novel method for solution of coupled radial Schrodinger equations
  • 2011
  • Ingår i: Physics of Atomic Nuclei. - 1562-692X .- 1063-7788. ; 74:8, s. 1151-1161
  • Tidskriftsartikel (refereegranskat)abstract
    • One of the major problems in numerical solution of coupled differential equations is the maintenance of linear independence for different sets of solution vectors. A novel method for solution of radial Schrodinger equations is suggested. It consists of rearrangement of coupled equations in a way that is appropriate to avoid usual numerical instabilities associated with components of the wave function in their classically forbidden regions. Applications of the new method for nuclear structure calculations within the hyperspherical harmonics approach are given. RAMOWITZ M, 1964
  •  
23.
  • Vaagen, J.S., et al. (författare)
  • Lessons from two paradigmatic developments; Rutherford's nuclear atom and halo nuclei
  • 2012
  • Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 381:1, s. Art. no. 012049-
  • Konferensbidrag (refereegranskat)abstract
    • In its initial 1911 version, underpinned by discoveries in alpha-scattering experiments, Rutherford's atom model made a gross separation of neutral matter; A veil of light negative matter surrounding a tiny impenetrable heavy positive core. The model had however little to say about the atomic (electronic) architecture and dynamics, hence did not make it straight to the catwalk of physics of those days. Three quarters of a century later, in 1985, new discoveries in collision experiments revealed existence of abnormally large light nuclei, but could say less about the nuclear architecture. History sometimes repeats itself: Like Bohr's ad hoc planetary model (1913) changed the fate of Rutherford's discovery, again Scandinavian inspired ideas on architecture, this time nuclear halos, changed our paradigm for the heart of matter. We comment on the need for a concerted Rutherfordian effort between theory and increasingly complete reaction experiments if further ground-breaking progress is going to be made in halo physics, and physics in vicinities of neutron and proton driplines, and generally in the more widely growing field of many-body open quantum systems, where structure and reactions come together. © Published under licence by IOP Publishing Ltd.
  •  
24.
  • Vaagen, J.S., et al. (författare)
  • Paradigmatic lessons from nuclear driplines
  • 2015
  • Ingår i: Nuclear Physics: Present and Future. - Cham : Springer International Publishing. - 9783319101996 ; , s. 69-78
  • Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
    • Science is—as emphasized 50 years ago by ThomasKuhn in his academic bestseller The Structure of Scientific Revolutions—driven by paradigms, rooted in outstanding discoveries and practice. At the centennial for the nuclear atom, it may be appropriate to address the current paradigmatic situation for nuclear physics on background of the large investmentsmade during the last decades. Following Rutherford’s paradigm, nuclear physics has developed by colliding nuclei and from studying the fragments that emerge. With restriction to new forms of transient cold nuclear matter, we will address if and how new discoveries have influenced the way we think about nuclear architecture, drawing parallels with comparable development in other branches of science. Recent discoveries in halo nuclei,11Be and the Borromean22C will serve as our cardinal examples. The challenges at driplines may appear less dramatic than what calls for a Kuhnian turnover, still we hope to convey that valuable lessons may be learned. The attention-grabbing dripline lessons we address are rooted in emergent degrees of freedom involving cluster constituents. This is a great challenge for the ruling paradigm, a shell-model inspired ab initio nucleon-based theory, developed and tested for stable nuclei, and currently being tuned to encompass dripline lessons. Our mental pictures and dynamic understanding of many of the outstanding dripline phenomena will, however, remain linked to cluster degrees of freedom. This duality makes our paradigmatic lessons conceptually less dramatic than what Kuhn’s “incommensurability” may imply.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-24 av 24

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy