共查询到20条相似文献,搜索用时 46 毫秒
1.
V. K. Lukyanov E. V. Zemlyanaya K. V. Lukyanov D. N. Kadrev A. N. Antonov M. K. Gaidarov 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(4):495-499
The 6He + 12C elastic scattering at E = 3.0, 38.3, and 41.6 MeV/nucleon is analyzed using the microscopic model of optical potential. According to this approach,
two or three parameters are fitted that renormalize the depth of real, imaginary, and surface parts of the calculated optical
potential. In this case, the ambiguity of the obtained sets of fitting parameters remains, but can be reduced by introducing
an additional criterion of selection: the dependence of the volume integrals of the optical potential on the energy. The structure
of the obtained optical potential, the role of the nuclear medium, the formation of the imaginary part of the optical potential,
and the interconnection between the surface potential and the 6He breakup channels are discussed. 相似文献
2.
K. Schwarz C. Samanta M. Fujiwara H. Rebel R. De Leo N. Matsuoka H. Utsunomiya H. Akimune I. Daito H. Fujimura F. Ihara K. Ishibashi Y. Maeda T. Yamanaka H. Yoshida A. Okihana T. Yoshimura P.K.J. van Aarle W.A.T. Uijen M. Ito Y. Sakuragi 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):367-375
Elastic scattering and inclusive breakup of 6Li particles on 12C, 58Ni, 90Zr, and 208Pb targets are measured at 100A MeV. The elastic scattering data are compared with single channel and Coupled Discretized
Continuum Channels calculations. The coupling-effect between the elastic and the breakup channels is important even at an
incident energy of 100A MeV and cannot be neglected. The inclusive breakup data are investigated for orbital dispersion effects
which are found to be less significant at 100A MeV. The longitudinal momentum distributions are broader than predicted by
theoretical expectations.
Received: 17 December 1999 / Revised version: 9 February 2000 相似文献
3.
The Coulomb dipole induced dynamic polarization potentials for 6He + 209Bi and 11Li + 208Pb systems within the framework of Feshbach’s formalism with a motive to ascertain the presence or absence of threshold anomaly
have been studied. As a result of this study, the threshold anomaly has been found to be present for both systems. It has
also been found that at deep sub-barrier energies the imaginary part either starts increasing or at least remains unchanged
which indicates the presence of the breakup threshold anomaly. In addition, the Coulomb breakup transmission factors for both
systems have been found to have maximum value below and near-barrier energies, but at very high energies due to closure of
the breakup channel the breakup transmission coefficients quickly becomes zero. 相似文献
4.
M. J.G. Borge M. Alcorta H. O.U. Fynbo G. Garcia H. B. Jeppesen O. Kirsebom M. Madurga G. Nyman D. Obradors O. Tengblad 《The European physical journal. Special topics》2007,150(1):207-210
We have studied 12C in full kinematics via the 10B(3He,pααα)
reaction at an energy of 2.45 MeV. In our data we have identified states in 12C
from the ground state up to about 18 MeV, with spins ranging from 0 to 4.
Due to the very good resolution, we are able to determine properties of
these 12C resonances, such as their energy, width, and spin.
In this contribution preliminary results from the ongoing analysis are presented.
Main focus on the precise determination of the breakup spectra for all resonances. 相似文献
5.
Yu. B. Gurov B. A. Chernyshev S. V. Isakov V. S. Karpukhin S. V. Lapushkin I. V. Laukhin V. A. Pechkurov N. O. Poroshin V. G. Sandukovsky 《The European Physical Journal A - Hadrons and Nuclei》2007,32(3):261-266
Experimental search for superheavy hydrogen isotopes 6H and 7H was performed in the stopped pion absorption on 9Be and 11B nuclei. The structures in the missing-mass spectra were observed in the reaction channels 9Be(π-, pd )X and 11B(π-, p4He)X . Four states of 6H were proposed. Evidences for 7H formation were obtained in the reaction channels 9Be(π-, pp)X and 11B(π-, p3He)X . 相似文献
6.
R. Álvarez-Rodrıguez E. Garrido A. S. Jensen D. V. Fedorov H. O. U. Fynbo 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):303-317
The hyperspherical adiabatic expansion is combined with complex scaling and used to calculate low-lying nuclear resonances
of 12C in the 3α model. We use Ali-Bodmer potentials and compare results for other potentials α-α with similar 8Be properties. A three-body potential is used to adjust the 12C resonance positions to desired values extending the applicability of the method to many-body systems decaying into three
α-particles. For natural choices of three-body potentials we find 14 resonances below the proton separation threshold, i.e. two 0+, three 2+, two 4+, one of each of 1±, 2-, 3±, 4-, and 6+. The partial-wave decomposition of each resonance is calculated as a function of the hyperradius. Strong variation is found
from small to large distance. The connection to previous experimental and theoretical results is discussed and agreements
as well as disagreements are emphasized. 相似文献
7.
8.
H. G. Bohlen R. Kalpakchieva W. von Oertzen T. N. Massey A. A. Ogloblin G. de Angelis M. Milin Ch. Schulz Tz. Kokalova C. Wheldon 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):279-302
The structure of 17C has been investigated using the three-neutron transfer reaction (12C,9C) on a 14C target at 231MeV incident energy, the reaction Q-value is Q
0 = - 46.930MeV. Eleven new states up to 16.3MeV excitation energy were identified. The same reaction has also been used on
a 12C target ( Q
0 = - 38.787MeV), and excited states in 15C up to 19MeV were observed. In 17C the three transferred neutrons populate (sd )3 configurations on the 14C core. The comparison of levels populated by the (12C,9C) reaction in 17C, 16C and 15C reveals a strong similarity of their properties. This concerns especially nine states in each of the three carbon isotopes,
which show practically the same excitation energies except a constant mean shift of +5.82MeV for 16C and +6.65MeV for 15C with respect to 17C. The triples of states from the three isotopes, which correspond to each other, have also similar widths and cross-section
ratios. It is concluded that the same (sd )3 structures are populated in the three carbon isotopes. The observed levels of 17C are also compared to the levels of 19O with known assignments and to shell model calculations, and their decay properties are discussed. 相似文献
9.
P. Mohr 《The European Physical Journal A - Hadrons and Nuclei》2007,34(1):23-28
α-decay half-lives for 104, 105, 106Te and 108, 109, 110Xe close above the doubly-magic 100Sn are calculated from systematic double-folding potentials. The derived α preformation factors are compared to results for
212, 213, 214Po and 216, 217, 218Rn above the doubly-magic 208Pb. α-decay energies of Q
α = 5.42±0.07MeV and 4.65±0.15MeV are predicted for 104Te and 108Xe; the corresponding half-lives are T
1/2 ≈ 5ns for 104Te and of the order of 60μs for 108Xe. Additionally, the properties of rotational bands in 104Te are analyzed, and the first excited 2+ state in 104Te is predicted at E
x = 650±40keV; it decays preferentially by γ emission with a reduced transition strength of 10 Weisskopf units to the ground
state of 104Te and with a minor branch by α emission to the ground state of 100Sn. 相似文献
10.
M. A. Naumenko V. V. Samarin Yu. E. Penionzhkevich N. K. Skobelev 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(6):710-716
Experimental cross sections of formation of isotopes 46Sc (in reaction 6He + 45Sc), 196,198Au (in reaction 6He + 197Au), and 65Zn (in reaction 6He + 64Zn) are analyzed. The time-dependent Schrödinger equation for the outer neutrons of 6He and 197Au nuclei is solved numerically to calculate the probability of neutron transfer and transfer cross sections. In reaction 6He + 197Au, the contribution of fusion and subsequent evaporation to experimental data can be neglected, while the corresponding contributions to reactions 6He + 45Sc and 6He + 64Zn are considerable. Fusion–evaporation is taken into account using the computational code of the NRV knowledge base. The results of calculations are in satisfactory agreement with the experimental data. 相似文献
11.
12.
Aparajita Dey S. Bhattacharya C. Bhattacharya K. Banerjee T. K. Rana S. Kundu S. R. Banerjee S. Mukhopadhyay D. Gupta R. Saha 《The European Physical Journal A - Hadrons and Nuclei》2009,41(1):39-51
Inclusive energy distributions for light charged particles (p , d , t and have been measured in the 20Ne (158, 170, 180, 200 MeV) + 12C
reactionsintheangularrange$10°$ - - $50°$.Exclusivelight-charged-particleenergydistributionmeasurementswerealsodoneforthesamesystemat158 MeVbombardingenergybyin - planelightchargedparticle - - fragmentcoincidence.Pre - equilibriumcomponentshavebeenseparatedoutfromprotonenergyspectrausingthemovingsourcemodelconsideringtwosources.ThedatahavebeencomparedwiththepredictionsofthestatisticalmodelcodeCASCADE.Ithasbeenobservedthatsignificantdeformationeffectswereneededtobeintroducedinthecompoundnucleusinordertoexplaintheshapeoftheevaporated$d$,$t$energyspectra.Forprotons, evaporatedenergyspectrawereratherinsensitivetonucleardeformation, thoughangulardistributionscouldnotbeexplainedwithoutdeformation.Thedecaysequenceofthehot$32S$nucleushasbeeninvestigatedthroughexclusivelight - - charged - particlemeasurementsusingthe$20Ne$$(158 MeV) + $12C
reaction. Information on the sequential decay chain has been extracted through a comparison of the experimental data with
the predictions of the statistical model. It is observed from the present analysis that exclusive light-charged-particle data
may be used as a powerful tool to probe the decay sequence of hot light compound systems. 相似文献
13.
M. Shibata O. Suematsu Y. Kojima K. Kawade A. Taniguchi Y. Kawase 《The European Physical Journal A - Hadrons and Nuclei》2007,31(2):171-176
An M3 transition in a doubly odd nucleus of 156Pm was identified by internal conversion electron measurement through the β-decay of 156Nd which was separated from the fission products of 235U using the on-line mass separator KUR-ISOL. The isomeric state at 150.3keV de-excites to the ground state with the M3 transition, and the spin-parity is considered to be 1-. Nilsson configurations are also discussed on the basis of the systematics. 相似文献
14.
The effect of polarization of the 6Li and 3H clusters on the parameters of states of the 7Li nucleus and on the cross section for the reaction 6Li(n,3H)4He was studied. The 4He + d + n three-cluster configuration was invoked for this purpose, and cluster dynamics was determined within a microscopic model
where the relative motion of the clusters was described in terms of Faddeev amplitudes. The 4He + d + n three-cluster configuration made it possible to consider the 4He + 3H and 6Li + n binary channels, which are dominant in 7Li, and to take simultaneously into account the cluster polarization of 6Li as a two-cluster subsystemin the 4He + d representation and the cluster polarization of 3Has a two-cluster subsystem in the d + n representation. 相似文献
15.
M. A. Cardona B. Roussière J. Libert J. Genevey J. Sauvage the ISOCELE ISOLDE Collaborations 《The European Physical Journal A - Hadrons and Nuclei》2007,31(2):141-154
Excited states in 182Os were populated by the β+/EC decay of 182Ir following mass separation. Gamma-ray and conversion electron spectroscopy techniques were employed. Monopole (E0) contributions were determined in transitions populating the ground-state band. A systematic study of the low-spin structures
in the Os isotopes is presented and a detailed analysis in the framework of a microscopic configuration mixing approach is
performed. 相似文献
16.
Shen Shuifa Fang Keming Gu Jiahui Liu Qingcheng Xu Furong 《The European Physical Journal A - Hadrons and Nuclei》2007,32(2):149-158
The decay of 95Ru has been investigated by means of γ-ray spectroscopy. The 95Ru nuclei were produced by the reaction 92Mo( α, n) 95Ru at a beam energy of 17MeV. High-purity Ge detectors have been used singly and in coincidence to study γ-rays in the decay of 95Ru to 95Tc. 132 γ-rays are reported, among them, energies and intensities for 127 transitions have been determined. A decay scheme of 95Ru with 31 levels is proposed which accommodates 127 of these transitions. Spins and parities for three new levels are proposed
from calculated log ft values, measured γ-ray branching ratios, and in-beam experiment results of the daughter nucleus 95Tc. Combining with the high-spin states observed by in-beam γ-ray spectroscopy of previous decay works, the structure of the excited states of 95Tc is discussed in the framework of the projected shell model. 相似文献
17.
Careful review of all the evidence makes it clear that at least three states are important at 12.4-MeV excitation in 20Ne (four, if the broad (2+) at 12.5 MeV is included). The three states are 3 - , 0 + , and 1 + (0+). The latter, which is quite strong in 19F (3He, d) singles, is probably the state observed in coincidence with 6.13-MeV γ-rays in 19F(3He, dγ).
Received: 19 August 2002 / Accepted: 28 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: fortune@physics.upenn.edu
Communicated by D. Guerreau 相似文献
18.
A. Korgul H. Mach B. A. Brown A. Covello A. Gargano B. Fogelberg W. Kurcewicz E. Werner-Malento R. Orlandi M. Sawicka 《The European Physical Journal A - Hadrons and Nuclei》2007,32(1):25-29
Recently the first excited state in 135Sb has been observed at the unexpectedly low excitation energy of only 282keV and interpreted as mainly d
5/2 proton coupled to the 134Sn core. Based on theoretical considerations it was suggested that its low excitation energy is related to a relative shift
of the proton d
5/2 and g
7/2 orbits induced by the neutron excess. We have measured the lifetime of the 282keV state by the advanced time-delayed βγγ(t) method. The measured half-life, T
1/2 = 6.1(4)ns, yields exceptionally low limits of B(M1;5/21
+→7/21
+)≤3.0×10-4
μ
2
N and B(E2;5/21
+→7/21
+)≤54e
2
fm
4. These strongly hindered M1 and slow E2 transition rates are similar to those for the transition de-populating the first excited state at 405keV in 211Bi. Results of shell model calculations with realistic interactions are presented. The M1 decay rate was found to be extremely sensistive both to the wave function and to the M1 effective operator. 相似文献
19.
N. A. Demekhina R. Kalpakchieva A. A. Kul’ko S. M. Luk’yanov N. K. Skobelev Z. Dlouhy V. Kroha A. Kugler T. V. Chuvilskaya A. A. Shirokova 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(6):777-781
Experimentally determined excitation functions of the transfer reactions producing 194–199Au and 197m
Hg isotopes during the interaction of 6Li with Pt nuclei are presented. An analysis of the experimental data as compared to EMPIRE-2.18 model calculations and experimental
results on the d + natPt and α + natPt reactions allow determination of the interaction channels of d- and α-clusters in 6Li with the target nucleus. The results from model calculations of the reaction cross sections appear considerably lower than
the experimental data. This discrepancy in describing the reactions with weakly bound nuclei is probably associated with the
incomplete consideration of various interaction channels in the EMPERE-2.18 software. It is clear that a complete understanding
of the interaction pattern in these processes requires consideration of the direct channels of 6Li nucleus cluster transfer during 6Li breakup near the Coulomb barrier. 相似文献
20.
N. Buforn A. Astier J. Meyer M. Meyer S. Perriès N. Redon O. Stézowski M.G. Porquet I. Deloncle A. Bauchet J. Duprat B.J.P. Gall C. Gautherin E. Gueorguieva F. Hoellinger T. Kutsarova R. Lucas A. Minkova N. Schulz H. Sergolle Ts. Venkova A.N. Wilson 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):347-353
High-spin states in 113-116Cd have been investigated with the fusion-fission reaction 28Si +176Yb at 145 > MeV. The experiment has been performed with the Eurogam2 array. New rotational bands based on two quasi-particle
states have been observed for even-even cadmium isotopes. A new level scheme based on the 11/2− isomeric state is proposed for 115Cd and the one of 113Cd has been extended to spin (31/2−). The decoupled bands identified in both odd-A nuclei are interpreted as being built upon a low-Ωh11/2 quasi-neutron configuration. Microscopic Hartree-Fock + BCS calculations confirm the prolate deformation in this mass region
especially for the odd cadmium isotopes.
Received: 21 December 1999 / Revised version: 16 February 2000 相似文献