共查询到20条相似文献,搜索用时 31 毫秒
1.
R. Lednicky 《Physics of Atomic Nuclei》2008,71(9):1514-1517
One of the basic facilities at the Joint Institute for Nuclear Research (JINR) in Dubna is the 6 A GeV Nuclotron, which has replaced the old weak focusing 10-GeV proton accelerator Synchrophasotron. The first relativistic
nuclear beams with the energy of 4.2 A GeV were obtained at the Synchrophasotron in 1971. Since that time, relativistic nuclear physics has been one of the main
directions of the JINR research program. In the coming years, the new JINR flagship program assumes the experimental study
of hot and dense strongly interacting QCD matter at the new JINR facility. This goal is proposed to be reached by (i) development
of the existing Nuclotron accelerator facility as a basis for generation of intense beams over atomic mass range from protons
to uranium and light polarized ions, (ii) design and construction of the Nuclotron-based heavy Ion Collider fAcility (NICA)
with the maximum nucleon-nucleon center-of-mass collision energy of √s
NN
= 9 GeV and averaged luminosity 1027 cm−2 s−1, and (iii) design and construction of the Multipurpose Particle Detector (MPD) at intersecting beams. Realization of the
project will lead to unique conditions for research activity of the world community. The NICA energy region is of major interest
because the highest nuclear (baryonic) density under laboratory conditions can be reached there. Generation of intense polarized
light nuclear beams aimed at investigation of polarization phenomena at the Nuclotron is foreseen.
The text was submitted by the author in English. 相似文献
2.
Peter Egelhof 《Pramana》1999,53(3):365-380
The investigation of direct reactions with exotic beams in inverse kinematics gives access to a wide field of nuclear structure
studies in the region far off stability. The basic concept and the methods involved are briefly discussed. The present contribution
will focus on the investigation of light neutron-rich halo nuclei. Such nuclei reveal a new type of nuclear structure, namely
an extended neutron distribution surrounding a nuclear core. An overview on this phenomenon, and on the various methods which
gave first evidence and qualitative confirmation of our present picture of halo nuclei, is given.
To obtain more quantitative information on the radial shape of halo nuclei, elastic proton scattering on neutron-rich light
nuclei at intermediate energies was recently investigated for the first time. This method is demonstrated to be an effective
means for studying the nuclear matter distributions of such nuclei. The results on the nuclear matter radii of 6He and 8He, the deduced nuclear matter density distributions, and the significance of the data on the halo structure is discussed.
The present data allow also a sensitive test of theoretical model calculations on the structure of neutron-rich helium isotopes.
A few examples are presented.
The investigation of few-nucleon transfer reactions in inverse kinematics may provide new and complementary information on
nuclear structure, as well as astrophysical questions. The physics motivation and the experimental concept for such experiments,
to be performed due to momentum matching reasons at low incident energies around 5–20 MeV/u at the new generation low energy
radioactive beam facilities SPIRAL, PIAFE, etc., is briefly discussed. 相似文献
3.
V. Bradnova M. M. Chernyavsky L. Just S. P. Kharlamov A. D. Kovalenko M. Haiduc K. A. Kotel’nikov V. A. Krasnov V. G. Larionova F. G. Lepekhin A. I. Malakhov G. I. Orlova N. G. Peresadko N. G. Polukhina P. A. Rukoyatkin V. V. Rusakova N. A. Salmanova B. B. Simonov S. Vokal P. I. Zarubin 《Physics of Atomic Nuclei》2003,66(9):1646-1650
A physical program of irradiation of emulsions in beams of relativistic nuclei named the BECQUEREL Project is reviewed. It is destined to study in detail the processes of relativistic fragmentation of light radioactive and stable nuclei. The expected results would make it possible to answer some topical questions concerning the cluster structure of light nuclei. Owing to the best spatial resolution, the nuclear emulsions would enable one to obtain unique and evident results. The most important irradiations will be performed in the secondary beams of He, Be, B, C, and N radioactive nuclei formed on the basis of JINR Nuclotron beams of stable nuclei. We present results on the charged state topology of relativistic fragmentation of the 10B nucleus at low energy-momentum transfers as the first step of the research. 相似文献
4.
G. Belovitsky E. Konobeevski A. Stepanov V. Zavarzina S. Zuyev N. Polukhina N. Starkov S. Lukyanov Yu. Sobolev 《The European physical journal. Special topics》2007,150(1):5-7
To estimate the probability of two-neutron
configurations in halo nuclei, we propose an experimental method
of studying neutron-neutron correlations at periphery of such
nuclei by measuring two-neutron transfer reaction. The
experimental study of 6He + A ↦ 4He + B for various targets
is performed using 6He beam of Flerov Laboratory of Nuclear
Reactions (JINR, Dubna) at energy of about 15 MeV/u and technique
of nuclear photoemulsions. Searching for events of two-nucleon
transfer reaction and their processing is performed using the
PAVICOM-setup at P.N. Lebedev Physical Institute. 相似文献
5.
Since the early 1970s, experiments have been performed to investigate the fragmentation of the lightest nuclei (d, 3H, 3He, and 4He) on protons at intermediate energies (~0.2–2 GeV per nucleon). These experiments were set up in ITEP and LHE JINR and realized in an exclusive approach with the help of liquid hydrogen bubble chambers. This investigation is of great interest from two points of view: first, the possibility of detailed theoretical analysis of the data obtained in 4π geometry on the basis of a good understanding of the structure of the wavefunctions of these nuclei and, second, the search for exotic interaction mechanisms. This overview presents the latest, most interesting results of the ITEP experiment on the study of 4Hep interactions at 4He momenta of 2.7 and 5 GeV/c, on cross sections, elastic scattering, pair correlations of secondary nucleons, cumulative production of nucleons and the lightest nuclei (d, 3H, and 3He), the main features of exclusive reactions, and the search for possible multiquark bag production (dibaryons and tribaryons). The essential results of the independent JINR experiment at 8.6 and 13.6 GeV/c also come under discussion. 相似文献
6.
M. Finger T. I. Kracíková N. A. Lebedev V. N. Pavlov I. Procházka V. M. Tsupko-Sitnikov Z. Janout J. Koníček M. Rotter B. Sedlák J. Dupák 《Hyperfine Interactions》1985,22(1-4):461-473
The experimental facility for the study of the decay of oriented nuclei in a broad range of atomic and mass number and half-lives based on hyperfine interactions at ultralow temperatures — the SPIN facility at JINR — is described. High cooling power top loading 3He-4He dilution refrigerator of the system is capable of fast cooling of the sample inserted into the mixing chamber to the base temperature 10 mK for about 1–2 h. Detection system is designed for the study of angular distribution and temperature dependence of the anisotropy of gamma rays, linear polarisation of gamma rays and NMR/ON studies. Some results of nuclear orientation studies in off-line mode of radioactive nuclei with the half-live down to 1 h produced by spallation reaction with 660 MeV protons are presented. The project of nuclear orientation system on-line to the mass-separator and the new 600 MeV Dubna proton phasotron is described. 相似文献
7.
E. Konobeevski G. Belovitsky A. Stepanov V. Zavarzina S. Zuyev N. Polukhina A. Rusetsky N. Starkov S. Lukyanov Yu. Sobolev 《Few-Body Systems》2008,44(1-4):277-280
To investigate the structure of the halo of Borromean nuclei, we have studied quasi-free scattering of the proton by constituents of halo-nuclei 6He. The experimental study is performed using the 6He beam of the Flerov Laboratory of Nuclear Reactions (JINR) at an energy of about 10?MeV/u and the technique of nuclear photoemulsions. Searching for events of quasi-free scattering and their processing is performed using the PAVICOM-setup at the Lebedev Physical Institute. 相似文献
8.
G. D. Kabdrakhimova Yu. G. Sobolev I. N. Kuhtina K. A. Kuterbekov K. O. Mendibaev Yu. E. Penionzhkevich 《Physics of Atomic Nuclei》2017,80(1):32-37
Experimental excitation functions in terms of the total cross sections for 6He + Si nuclear reactions are analyzed in the energy range between 5 and 50 MeV/А, and a brief survey of the procedures used to obtain experimental data is given. Particular attention is given to describing experiments performed in beams of radioactive nuclei from the accelerators of the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research (JINR, Dubna). The experimental data in question are analyzed on the basis of a semimicroscopic optical model. 相似文献
9.
In the present work, quantitative calculations were carried out for production and depletion of the 93m Mo isomer in a relatively simple experiment using 91Zr beam ions. Such studies could be arranged at existing and operating accelerator facilities, e.g. at GSI or in JINR. The 93m Mo nuclei produced in a He gas target due to the 4He(91Zr, 2n) reaction will recoil into a gas stopper with a high velocity, being then depleted due to NEEC in highly-ionized species. 相似文献
10.
V. I. Zagrebaev Yu. G. Teterev V. I. Zhemenik G. V. Mishinsky S. V. Mitrofanov S. N. Dmitriev 《Physics of Particles and Nuclei Letters》2010,7(2):127-131
The possibility of producing exotic 6He nuclei in the 7Li(γ, p) reaction with 22 MeV electron beam at the MT-25 microtron in the Flerov Laboratory of Nuclear Reactions, Joint Institute
for Nuclear Research (FLNR JINR), is studied. The 6He yield from the Li2CO3 target made up 6 × 105 s−1 per 1 μA of the electron beam current. The obtained result is quite promising, taking into account the further improvement
of the target unit, the possibility of using another lithium compound, and the increase in the target material temperature
and the electron beam current up to 20 μA. The application of this approach for the further production of a monochromatic
beam of accelerated 6He nuclei with an intensity on the order of 107 s−1 would make a large number of experiments on investigating the structure of this nucleus and the mechanisms of nuclear reactions
with its participation feasible. This method for obtaining 6He nuclei may turn out to be one of the most optimal (and inexpensive) currently available. 相似文献
11.
V. D. Kekelidze A. D. Kovalenko I. N. Meshkov A. S. Sorin G. V. Trubnikov 《Physics of Atomic Nuclei》2012,75(5):542-545
A new scientific program is proposed at the Joint Institute for Nuclear Research (JINR) in Dubna aimed at studies of hot and dense baryonic matter in the wide energy range from 2 GeV/u kinetic energy in fixed target experiments to $\sqrt {s_{NN} } = 4 - 11$ GeV/u in the collider mode. To realize this program the development of the JINR accelerator facility in high-energy physics (HEP) has been started. This facility is based on the existing superconducting synchrotron??the Nuclotron. The program foresees both experiments at the beams extracted from the Nuclotron, and the construction of a heavy-ion collider??the Nuclotron-based Ion Collider fAcility (NICA) which is designed to reach the required parameters with an average luminosity of L = 1027 cm?2 s?1. 相似文献
12.
R. V. Jolos 《Physics of Atomic Nuclei》2001,64(6):1127-1133
13.
Quadrupole-interaction nuclear orientation experiments have been performed on182Ta (jπ=3?1; T1/2=115d) in 2H-TaS2. γ-anisotropies up to ~ 30 % have been observed at a temperature of ~ 8 mK, which, however, is only about half of the value expected taking into account known results of TDPAC measurements on181Ta in 2H-TaS2. In principle, matrices of dichalcogenides could be well suited for nuclear quadrupole resonance on oriented nuclei (NQR-ON) experiments. 相似文献
14.
Thomas Stöhlker Yuri A. Litvinov Angela Bräuning-Demian Michael Lestinsky Frank Herfurth Rudolf Maier Dieter Prasuhn Reinhold Schuch Markus Steck 《Hyperfine Interactions》2014,227(1-3):45-53
SPARC collaboration at FAIR pursues the worldwide unique research program by utilizing storage ring and trapping facilities for highly-charged heavy ions. The main focus is laid on the exploration of the physics at strong, ultra-short electromagnetic fields including the fundamental interactions between electrons and heavy nuclei as well as on the experiments at the border between nuclear and atomic physics. Very recently SPARC worked out a realization scheme for experiments with highly-charged heavy-ions at relativistic energies in the High-Energy Storage Ring HESR and at very low-energies at the CRYRING coupled to the present ESR. Both facilities provide unprecedented physics opportunities already at the very early stage of FAIR operation. The installation of CRYRING, dedicated Low-energy Storage Ring (LSR) for FLAIR, may even enable a much earlier realisation of the physics program of FLAIR with slow anti-protons. 相似文献
15.
Yu. E. Penionzhkevich 《Physics of Atomic Nuclei》2014,77(11):1400-1414
Some results of investigations into a new nuclear-physics field associated with the production of radioactive nuclear beams and physical studies with these beams are presented. The most recent results obtained by studying the structure of nuclei and reaction mechanisms with radioactive nuclear beams are surveyed. Data obtained in Dubna at the DRIBs accelerator complex are presented along with allied results from other research centers. In this connection, existing experimental data on light loosely bound exotic nuclei are discussed. The parameters of DRIBs3, which is a new accelerator complex, are presented, and the physics research program that will be implemented with the aid of new setups, including a high-resolution magnetic analyzer (MAVR) and a 4π neutron detector (TETRA), is described. A collaboration in the realms of employing radioactive nuclear beams at the DRIBs complex together with other accelerator complexes [SPIRAL2 (France), RIKEN (Japan), FAIR (Germany), and RIBF (CIIIA)] on the basis of employing new highly efficient experimental facilities has already led to the discovery of new phenomena in nuclear physics and will make it possible to study in the future new regions of nuclear matter in extreme states. 相似文献
16.
Excited states of atomic nuclei can have long half lives, due to the angular-momentum couplings of unpaired nucleons. Such
isomeric states provide opportunities for exploring novel nuclear physics, astrophysics and physics at the atomic/nuclear interface.
This review focuses on the properties of isomers in deformed nuclei, and emphasises the importance of axial symmetry in preserving
the integrity of the K quantum number. A region of neutron-rich nuclei around 188Hf (Z=72, N=116) is predicted to have exceptional isomer properties, and experimental advances are now opening up this region to detailed
investigation.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
18.
19.
N. G. Peresadko Yu. A. Alexandrov S. G. Gerasimov V. A. Dronov V. G. Larionova A. V. Pisetskaya E. I. Tamm V. N. Fetisov S. P. Kharlamov L. N. Shesterkina 《Physics of Atomic Nuclei》2010,73(11):1942-1947
In a track nuclear photoemulsion exposed to a beam of 7Li nuclei accelerated to a momentum of 3 GeV/c per nucleon at the synchrophasotron of the Joint Institute for Nuclear Research (JINR, Dubna), 13 events in which 7Li nuclei interacting with protons break up into 3H and 4He fragments were detected among 3730 inelastic-interaction events. For this fragmentation channel, the cross section was
found to be 8 ± 2 mb. The average value of the fragment total transverse momentum was 214 ± 5 MeV/c. This value exceeds markedly the average value of the transverse-momentum transfer in the coherent dissociation of 7Li nuclei on track-emulsion nuclei (166±5MeV/c). The recoil-proton transverse momentum was on average 98% of the total proton momentum. The longitudinal-momentum distribution
of protons was characterized by a variance of 16 MeV/c and a mean value of 37 ± 2MeV/c. 相似文献
20.
R. Kalpakchieva V. A. Maslov R. A. Astabatian A. A. Kulko S. M. Lukyanov E. R. Markarian Yu. Ts. Oganessian Yu. E. Penionzhkevich N. K. Skobelev Yu. G. Sobolev 《Physics of Atomic Nuclei》2007,70(4):619-625
Experimental data on the momentum distributions of 4He nuclei originating from 6He and 6Li breakup on various targets are presented over a wide beam energy range. The experiment with 6He was performed at the DRIBs accelerator complex for radioactive beams at the Joint Institute for Nuclear Research (JINR, Dubna). The intensity of the 6He beam used was 5 × 106 particles per second and its energy was 10 MeV per nucleon. The momentum distributions of breakup products were measured by means of the MSP-144 magnetic spectrometer. The distribution width was shown to be virtually independent of the target mass. A small value of this width, σ ~ 28 MeV/c, confirms the presence of a halo in 6He. The measurements performed with 6Li beams of energy 18 and 46 MeV per nucleon at the U-400M accelerator yielded a width value of σ ~ 50 MeV/c for the momentum distributions of 4He nuclei, which is intermediate between that for 6He and those for stable nuclei. A compilation of the widths of the momentum distributions of fragments originating from the breakup of various nuclei is presented versus the binding energy of one or two neutrons in these nuclei, the target mass and the projectile energy. 相似文献