共查询到20条相似文献,搜索用时 15 毫秒
1.
The effect of inelastic excitation of exotic light projectiles (proton-as well as neutron-rich)17F and11Be on fusion with heavy target has been studied at near-barrier energies. The calculations have been performed in the coupled
channels approach where, in addition to the normal coupling of the ground state of the projectile to the continuum, inelastic
excitation of the projectile to the bound excited state and its coupling to the continuum have also been taken into consideration.
The inclusion of these additional couplings has been found to have significant effect on the fusion excitation function of
neutron-rich11Be on208Pb whereas the effect has been observed to be nominal for the case of proton-rich17F on the same target. The pronounced effect of the channel coupling on the fusion process in the case of11Be is attributed to its well-developed halo structure. 相似文献
2.
Pioneering experiments with stored and cooled exotic nuclei at relativistic energies have been performed using the combination
of the fragment separator FRS with the storage-cooler ring ESR. Exotic nuclei created in peripheral collisions are spatially
separated in-flight and injected into the storage ring for high-precision mass and unique lifetime measurements. Lifetimes
of stored bare and few-electron nuclei have been measured to study the influence of the electron density on the β decay. This
condition, relevant for stellar plasma, can now be systematically investigated in the laboratory for the first time. Characteristic
experiments of the present FRS-ESR system are presented and perspectives for a next-generation facility are briefly outlined.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
3.
From the spectroscopic information provided by single particle stripping reactions, we have extracted average effective two-body
interaction between nucleons in thep-, sd-, andfp- shells. Using the derived interaction parameters, we have calculated the energy centroids of the level spectra of residual
nuclei obtained via single nucleon stripping reactions involving light and medium mass nuclei as targets. 相似文献
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M. Y. H. Farag E. H. Esmael H. M. Maridi 《The European Physical Journal A - Hadrons and Nuclei》2012,48(11):1-17
The proton elastic scattering data on some light exotic nuclei, namely, 6, 8He, 9, 11Li, and 10, 11, 12Be, at energies below than 100MeV/nucleon are analyzed using the single folding optical model. The real, imaginary, and spin-orbit parts of the optical potential (OP) are constructed only from the folded potentials and their derivatives using M3Y effective nucleon-nucleon interaction. These OP parts, their renormalization factors and their volume integrals are studied. The surface and spin-orbit potentials are important to fit the experimental data. Three model densities for halo nuclei are used and the sensitivity of the cross-sections to these densities is tested. The imaginary OP within high-energy approximation is used and compared with the single folding OP. This OP with few and limited fitting parameters, which have systematic behavior with incident energy, successfully describes the proton elastic scattering data with exotic nuclei. 相似文献
7.
The exchange of low-lying collective vibrations between pairs of nucleons moving in time reversal states close to the Fermi energy provides a conspicuous contribution to the nuclear pairing interaction, which accounts for 30-50% of the pairing gap in the case of nuclei along the stability valley, and to essentially all of the pairing correlations of the most loosely bound nucleons in the case of halo nuclei.Received: 30 October 2002, Published online: 23 March 2004PACS:
21.30.Fe Forces in hadronic systems and effective interactions - 21.60.Jz Hartree-Fock and random-phase approximations 相似文献
8.
Maurizio Corradini Masaki Hori Takumi Kobayashi Marco Leali Evandro Lodi-Rizzini Valerio Mascagna Aldo Mozzanica Michela Prest Anna Soter Koichi Todoroki Erik Vallazza Luca Venturelli Nicola Zurlo 《Hyperfine Interactions》2012,213(1-3):31-39
The results of the annihilation cross sections measurement of 5.3 MeV antiprotons on nickel, tin, platinum and Mylar targets performed by the ASACUSA Collaboration at CERN are presented and compared with the existing data and models. From the experimental point of view the presented data are the first measurement of antinucleon annihilation cross sections at low energies obtained with a pulsed beam. This results open the road for the next measurements at the very low energies of the order of 100 keV that are in progress by the ASACUSA Collaboration. The experimental method foreseen for the 100 keV measurement is illustrated. 相似文献
9.
The stability (with respect to nucleon emission) of highly neutron-rich nuclei of He, C, O and Si is investigated in the framework of the Hartree-Fock approximation with several sets of Skyrme interactions. The existence (in the sense of stability against decay with the emission of a neutron) of as yet undetected 20C, 22C, 28O and 42Si nuclei is predicted. The relevance of the triplet-triplet component of the nuclear interaction to the stability of the neutron-rich nuclei is demonstrated. 相似文献
10.
J. S. Vaagen I. J. Thompson J. M. Bang M. V. Zhukov B. V. Danilin D. V. Fedorov 《Zeitschrift für Physik A Hadrons and Nuclei》1994,349(3-4):285-290
The discovery of light nuclei with neutron halos has opened new perspectives for nuclear structure and a possibility to study genuine few-body aspects of matter. A number of borromean systems where the system is bound but where no binary subsystems are bound, are realized by nature in the context of nuclei,11Li being the nucleus which has had most recent attention. Although a large number of calculations have addressed the detailed structure of the11Li neutron halo, no single model has yet explained all the data presently available. This is in part due to uncertainties in then+9Li interaction. For6He, also a borromean system, where then+core interaction is known, the best three-body and reaction models succeed in reproducing the data. In the11Li case, a major uncertainty concerns the effect of possible 1s intruder states. 相似文献
11.
Y. Iwata T. Otsuka J. A. Maruhn N. Itagaki 《The European Physical Journal A - Hadrons and Nuclei》2009,42(3):613-621
The charge equilibration upper energy-limit formula is proposed. It shows not only the basic mechanism of charge equilibration
but also does imply the possibility of controlling the exotic nuclear synthesis. To understand the mechanism of charge equilibration,
charge and mass distributions of final fragments of the heavy-ion collisions are studied based on three-dimensional time-dependent
Hartree-Fock calculations with a Skyrme interaction. 相似文献
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《Physics letters. [Part B]》1997,415(1):1-7
Slater determinants built from the single-particle eigenfunctions of the analytically solvable Ginocchio potential are used to approximate the self-consistent Hartree-Fock solutions for nuclei. The results indicate that this potential reproduces the mean field for a wide range of nuclei, including those far from stability. Properties sensitive to the surface are particularly well described, suggesting that the potential may be useful in shell-model studies of weakly-bound nuclei. 相似文献
15.
Yu. N. Uzikov 《JETP Letters》2002,75(1):5-8
Available data on large-angle nucleon-deuteron elastic scattering Nd→dN below the pion threshold give a signal for three-body forces. The problem exists of the separation of possible subtle aspects of these forces from off-shell effects in two-nucleon potentials. By considering the main mechanisms of the process Nd→dN, we show qualitatively that in the quasi-binary reaction N+d→(NN)+N with the final spin singlet nucleon-nucleon pair in the S-state, the relative contribution of the three-nucleon forces differs substantially from the elastic channel. It gives a new testing basis for the problem in question. 相似文献
16.
K. A. Kuterbekov A. M. Kabyshev I. Tleulessova G. A. Almanov A. M. Mukhambetzhan Yu. E. Penionzhkevich N. K. Skobelev Yu. G. Sobolev S. M. Lukyanov T. N. Nurakhmetov E. T. Abseitov B. M. Sadykov 《Physics of Atomic Nuclei》2014,77(5):581-586
The results of a joint analysis of experimental data (angular distributions for scattering and total reaction cross sections) are presented for the case of the interaction of 6,7Li ions with 28Si nuclei at energies between 7.5 and 32 MeV. The respective calculations were performed on the basis of a deformed potential of the optical model by using the SPI-GENOA code. The energy dependences of the parameters of the macroscopic optical model and the total cross section for the (6,7Li+28Si) reactions were obtained over the energy interval from 7.5 to 32 MeV. The calculated angular distributions and total reaction cross sections are in good agreement with experimental data. 相似文献
17.
S. Wan P. Reiter J. Cub H. Emling J. Gerl R. Schubart D. Schwalm 《Zeitschrift für Physik A Hadrons and Nuclei》1997,358(2):213-215
After the fragmentation reaction of 50Ti on 9Be at 330 MeV/u, more than 30 neutron-rich isotopes from B to Ca were selected by the fragment separator FRS at GSI. Peripheral collisions with a secondary Pb target at relativistic energies were used to study the excited states of these isotopes. De-excitation γ-rays were detected with the Darmstadt-Heidelberg Crystal Ball spectrometer. The first results demonstrate the feasibility of in-beam γ-spectroscopy at relativistic energies. 相似文献
18.
Angular distributions have been measured at energies near the Coulomb barrier for the systems 18O + 24Mg, 12C + 28Si and 16, 18O + 28Si for elastic scattering and inelastic scattering to the first 2+ states in 18O, 24Mg and 28Si. Coupled-channel calculations were required in order to reproduce the details of the strong Coulomb-nuclear interference minima. However, a satisfactory account of the main features of the data was obtained in a first-order DWBA analysis and with the closed formalism of Frahn. With the exception of 18O, it was sufficient to assume equal charge and optical-potential deformation lengths. 相似文献
19.
K S R Sarma K L Narasimham K Premchand S Bhuloka Reddy K Parthasaradhi V Lakshminarayana 《Pramana》1982,18(6):485-494
Total photon mass attenuation coefficients in C, Al, S, Ti, B2O3, LiF, ZnO, Y2O3 and H8O2C5 (perspex) are measured on a good geometry set-up using proportional counter, Si(Li) and Ge(Li) detecting systems in the energy
region from 6.47 to 52.014 keV employing x-rays and gamma rays from radioactive sources. The deduced photoelectric cross-sections
are found to agree with the theoretical values of Storm and Israel, Scofield and semiexperimental values of Veigele wherever
available within a few percent. The photo-electric cross-sections in elements, S, Ti and Y at their respectiveK-edges obtained by extrapolation technique agree with the theoretical values of Storm and Israel and Scofield at the respectiveK-edges except in S. In the case of S both the theoretical values atK-edges are found to be underestimations, more in the case of Scofield evaluations. 相似文献
20.
B. A. Urazbekov A. S. Denikin S. K. Sakhiev S. M. Lukyanov 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(6):690-694
Data on elastic and inelastic scattering, and the reactions of few-nucleon transfers in the interaction between the nuclei of deuteron and 9Be at energies of around 10 MeV/nucleon, are analyzed. A theoretical analysis is performed using the double-folding potential model with the wave function of the ground state of the 9Be nucleus, constructed in the three-cluster α + α + n-approximation. Calculations of the cross section of elastic scattering for the reaction d + 9Be using the calculated folding potential are preformed using the optical model. The resulting optical potential is used to analyze cross sections of transfer reactions and inelastic scattering in the context of the distorted waves method. A comparative analysis of the experimental data and theoretical calculations is performed. 相似文献