共查询到20条相似文献,搜索用时 15 毫秒
1.
J. Hakala R. Rodríguez-Guzmán V. -V. Elomaa T. Eronen A. Jokinen V. S. Kolhinen I. D. Moore H. Penttilä M. Reponen J. Rissanen A. Saastamoinen J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2011,47(10):1-12
Direct mass measurements with typical uncertainties of 1-10keV have been performed for the first time for ten neutron-rich isotopes 102, 103Y , 108Nb , 111Mo , 113, 114Tc , 116Ru , 119Rh , and 121, 122Pd . The obtained mass data compared with the 2003 atomic-mass evaluation shows systematic overestimation of binding energies far from stability. The relationship between two-neutron separation energies, nuclear structure and shape changes has been investigated by comparing the experimental data with a theoretical calculation based on the Hartree-Fock-Bogoliubov approximation using modern energy density functionals. 相似文献
2.
G. Lhersonneau J.C. Wang S. Hankonen P. Dendooven P. Jones R. Julin J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,2(1):25-27
The decays of 112Rh
g
and 112Rh
m
obtained as on-line mass separated fission products have been investigated by standard β and γ spectroscopic techniques and
γ-γ angular correlations. Low-lying 0+ and 2+ states are identified in the daughter nucleus 112Pd. Systematics suggests the existence of an intruder band which is the lowest in 110Pd, i.e. two neutrons before the midshell.
Received:13 March 1998 相似文献
3.
Collective properties of neutron-rich Ru, Pd, and Cd isotopes are reviewed, combining the original results from the IGISOL β-decay experiments with recent experimental and theoretical progress. The transitional nature of Ru and Pd nuclei is discussed via the low-lying level systematics, including the low-lying 0?+? states. Although the role of an anharmonic quadrupole vibrator in Cd nuclei was recently questioned, level systematics for the three-phonon quintuplet in 116,118,120Cd are presented, and an outlook of the spectroscopic methods for the level lifetime or B(E2) values is given. 相似文献
4.
H. G. Bohlen W. von Oertzen R. Kalpakchieva B. Gebauer S. M. Grimes T. N. Massey H. Lenske A. Lenz M. Milin Ch. Schulz T. Kokalova S. Torilov S. Thummerer 《Acta Physica Hungarica A》2003,18(2-4):179-184
The structure of neutron-rich beryllium isotopes has been investigated using different heavy-ion induced transfer reactions. A strong sensitivity to the chosen core nucleus is found for the cores of 9Be and 10Be, respectively. With a 9Be core, molecular rotational bands up to high excitation energies are observed due to the pronounced 2α-cluster structure, whereas only few states at low excitation energies are populated with a 10Be core. For 11Be a detailed investigation has been performed for the three states at 3.41 MeV, 3.89 MeV and 3.96 MeV, which resulted in the most probable spin-parity assignments 3/2+, 5/2? and 3/2?, respectively. Furthermore we have studied particlehole states of 16C using the 13C(12C,9C)16C reaction and found 14 previously unknown states. 相似文献
5.
H. L. Seifert J. M. Wouters D. J. Vieira H. Wollnik X. G. Zhou X. L. Tu Z. Y. Zhou G. W. Butler 《Zeitschrift für Physik A Hadrons and Nuclei》1994,349(1):25-32
The ground state masses of thirty-nine neutronrich nuclei from51Ca to72Ni have been measured using the Time-of-Flight Isochronous (TOFI) spectrometer. Eight of these masses have been measured for the first time and thirty-one are remeasurements of neutron-rich nuclei previously reported. Good agreement between these results and a previous TOFI experiment was observed except for the most neutron-rich isotopes of vanadium through iron with the present results being more bound and in better agreement with theory. The low binding energy of68Ni, as indicated by an unreasonably low two-neutron separation energy, suggests the presence of a high-lying, long-lived isomeric state in this nucleus. 相似文献
6.
E. Runte K.L. Gippert W.D. Schmidt-Ott P. Tidemand-Petersson L. Ziegeler R. Kirchner O. Klepper P.O. Larsson E. Roeckl D. Schardt N. Kaffrell P. Peuser M. Bernas P. Dessagne M. Langevin K. Rykaczewski 《Nuclear Physics A》1985,441(2):237-260
A 46 mg/cm2 thick natW target was irradiated with an 11.5 MeV/u 82Se beam. On-line massseparated samples of projectile-like neutron-rich products from multi-nucleon transfer reactions were investigated by βγ spectroscopy in the mass region A = 52–79. Decay properties of the nuclei 61Mn (0.71 s), 64Fe (2.0 s), 65Co (1.25 s), 69Ni (10 s) and 73mZn (5.8 s) were measured for the first time. For 67Ni a decay scheme could be constructed using information from new γ-transitions. The known decay schemes of 60Mn, 63Fe, 63Co and 69Cu were extended. New half-life values of neutron-rich isotopes are compared with theoretical predictions. 相似文献
7.
Carlos E. Vargas Víctor Velázquez Sergio Lerma 《The European Physical Journal A - Hadrons and Nuclei》2013,49(1):1-8
Microscopic studies in heavy nuclei are very scarce due to large valence spaces involved. This computational problem can be avoided by means of the use of symmetry-based models. Ground-state, γ and β bands, and their B(E2) transition strengths in 160–168Dy isotopes, are studied in the framework of the pseudo-SU(3) model which includes the preserving symmetry Q · Q term and the symmetry-breaking Nilsson and pairing terms, systematically parametrized. Additionally, three rotor-like terms are considered, whose free parameters, fixed for all members of the chain, are used to fine tune the moment of inertia of rotational bands and the band head of γ and β bands. The model succesfully describes in a systematic way rotational features in these nuclei and allows to extrapolate toward the midshell nucleus 170Dy. The results presented show that it is possible to study a full chain of isotopes or isotones in the region with the present model. 相似文献
8.
9.
R.R. Rodríguez-Guzmán J.L. Egido L.M. Robledo 《The European Physical Journal A - Hadrons and Nuclei》2003,17(1):37-47
The Angular Momentum Projected Generator Coordinate Method, with the quadrupole moment as collective coordinate and the Gogny
force (D1S) as the effective interaction, is used to describe the properties of the ground state and low-lying excited states
of the even-even neon isotopes 20-34Ne, that is, from the stability valley up to the drip line. It is found that the ground state of the N = 20 nucleus 30Ne is deformed but to a lesser extent than the N = 20 isotope of the magnesium. In the calculations, the isotope 32Ne is at the drip line in good agreement with other theoretical predictions. On the other hand, rather good agreement with
experimental data for many observables is obtained.
Received: 19 Novemeber 2002 / Accepted: 24 January 2003 / Published online: 8 April 2003 相似文献
10.
H. Ueno D. Kameda D. Nagae M. Takemura K. Asahi K. Shimada K. Takase T. Sugimoto T. Nagatomo M. Uchida T. Arai T. Inoue A. Yoshimi T. Kawamura K. Narita 《The European physical journal. Special topics》2007,150(1):185-186
Ground-state magnetic-dipole moments (μ) of 30-32Al and
electric quadrupole moments (Q) of 31,32Al have been measured
with the β-NMR method using spin-polarized radioactive-isotope
beams produced in projectile-fragmentation reactions. Beams of
30-32Al were obtained by using RIKEN projectile-fragment
separator RIPS after the fragmentation of 40Ar projectiles at an
energy of E = 95A MeV on a 93Nb target. The obtained
μexp[30-32Al] and
values agree well with shell-model calculations within the sd
shell using the USD interaction. Also, Qexp[31Al]
was found to be small. Thus, we can conclude that these aluminum
isotopes are located outside the island of inversion. 相似文献
11.
F. Ameil M. Bernas P. Armbruster S. Czajkowski P. Dessagne H. Geissel E. Hanelt C. Kozhuharov C. Miehe C. Donzaud A. Grewe A. Heinz Z. Janas M. de Jong W. Schwab S. Steinhäuser 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):275-283
The unknown β-decay half-lives of 22 isotopes far off stability (5 < T
Z
< 10) in the region from Ti to Ni were measured at GSI, Darmstadt. The nuclei were produced in a fragmentation reaction of
500 A.MeV 86Kr-projectile impinging on a thick Be target. The isotopes of interest were separated and identified with the fragment separator,
FRS, by a combination of Bρ,Z, and ToF techniques. An additional range separation was performed by a selective implantation
into granular detectors. The spatial and time correlations of the implant with the consecutively detected β-particles were
used to determine the unknown half-lives. For nuclei far off stability, β-decay chains were measured and analyzed as well,
leading to an even more reliable evaluation of the lifetimes. The large discrepancies found between the measured and the theoretical
values emphasize that most recent theoretical work is not an improvement over calculations made almost a decade ago.
Received: 1 October 1997 相似文献
12.
The electric quadrupole moment Q and the magnetic momentp(or the g factor) of low-lying states in even-even nuclei ~(72-80)Ge and odd-mass nuclei ~(75-79) Ge are studied in the framework of the nucleon pair approximation(NPA) of the shell model,assuming the monopole and quadrupole pairing plus quadrupole-quadrupole interaction.HA H.Our calculations reproduce well the experimental values of Q(2_1~+) and g(2_1~+) for ~(72,74,76) Ge,as well as the yrast energy levels of these isotopes.The structure of the 2_1~+ states and the contributions of the proton and neutron components in Q(2_1~+) and g(2_1~+) are discussed in the SD-pair truncated shell-model subspace.The overall trend of Q(2_1~+) and g(2_1~+)as a function of the mass number A,as well as their signs,are found to originate essentially from the proton contribution.The negative value of Q(2_1~+) in ~(72,74)Ge is suggested to be due to the enhanced quadrupole-quadrupole correlation and configuration mixing. 相似文献
13.
In view of recent experimental progress on production and spectroscopy of neutron-rich isotopes of Dy with mass number A =166
and 168, we have made theoretical investigations on the structure of high spin states of164-170Dy isotopes in the cranked Hartree-Fock-Bogoliubov (CHFB) theory employing a pairingquadrupolehexadecapole model interaction.
With the increase of neutron number the rotation alignment of the proton orbitals dominates the structure at high spins, which
is clearly reflected in the spin dependence of the rotational g-factors. A particularly striking feature is the difference
in the spin-dependent properties of166Dy as compared to that of164Dy 相似文献
14.
Results of several experiments aimed at exploring the nuclear spatial structure of neutron-rich He and Li isotopes are presented
and briefly discussed. The study of the density distributions in these nuclei by small-angle proton elastic scattering at
intermediate energy is considered in more detail. The performed investigations allow one to obtain information on the total
matter distributions, radii of the matter, neutron and proton distributions, effective and internal core sizes, halo sizes,
and spatial correlations of the halo nucleons in the studied nuclei.
The text was submitted by the authors in English. 相似文献
15.
H. G. Bohlen W. von Oertzen R. Kalpakchieva B. Gebauer S. M. Grimes A. Lenz T. N. Massey M. Milin Ch. Schulz Tz. Kokalova S. Torilov S. Thummerer 《Physics of Atomic Nuclei》2003,66(8):1494-1500
The structure of neutron-rich beryllium isotopes has been investigated using different heavy-ion-induced transfer reactions. In neutron transfer reactions, the population of final states shows a strong sensitivity to the chosen core nucleus, i.e., the target nuclei 9Be or 10Be, respectively. Molecular rotational bands up to high excitation energies are observed with 9Be as the core due to its pronounced 2α-cluster structure, whereas only a few states at low excitation energies are populated with 10Be as the core. For 11Be, a detailed investigation has been performed for the three states at 3.41, 3.89, and 3.96 MeV, which resulted in the most probable spin-parity assignments 3/2+, 5/2?, and 3/2?, respectively. Furthermore, we have studied particle-hole states of 16C using the 13C(12C, 9C)16C reaction and found 14 previously unknown states. Using the 12C(12C, 9C)15C reaction, five new states were observed for 15C. 相似文献
16.
17.
Structural evolution of odd-even and odd-odd Mn isotopes from the valley of stability up to neutron dripline is studied in the framework of the self-consistent mean-field theory of Hartree–Fock–Bogoliubov. Three Skyrme effective interactions, namely, SLy4, SLy5 and SLy5T, are employed to investigate the tensor force effect on the ground-state properties. It is shown that the calculated quantities with the SLy4 interaction correctly reproduce the available experimental data and agree well with finite range droplet model and relativistic mean-field predictions. An inconsistency has been observed between the curves of the separation energies and that of the charge radius around N = 40. It is explained by the flatness of the potential energy curves in this region. The SLy5 and SLy5T results point to the necessity to refit all the Skyrme parameters after including the tensor terms. 相似文献
18.
D. G. Burke H. Folger H. Gabelmann E. Hagebø P. Hill P. Hoff O. Jonsson N. Kaffrell W. Kurcewicz G. Løvhøiden K. Nybø G. Nyman H. Ravn K. Riisager J. Rogowski K. Steffensen T. F. Thorsteinsen ISOLDE Collaboration 《Zeitschrift für Physik A Hadrons and Nuclei》1989,333(2):131-135
Neutron-rich isotopes of astatine have been produced through spallation reactions with 600 MeV protons on a232Th target and identified by spectroscopic techniques combined with one-line mass separation at the ISOLDE facility. The half-lives of218At and219At have been remeasured to be 1.5(3) s and 57(4) s, respectively. Four new isotopes of astatine,220?223At, have been observed for the first time, and their half-lives were found to be 3.73(13) min, 2.3(2) min, 54(10) s, and 50(7) s, respectively. Another nuclide,216Bi, has been observed for the first time as the daughter product of the220At alpha decay, and its half-life has been measured to be 6.6(21) min. 相似文献
19.