共查询到20条相似文献,搜索用时 62 毫秒
1.
R.P. Singh R.K. Bhowmik S.S. Ghugre S.B. Patel 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):35-40
High spins states in 99Rh were populated via the 66Zn(37Cl, 2p2n)99Rh reaction at an incident beam energy of 130 MeV. Seventeen new transitions have been observed in the present study and the
level scheme has now been extended up to a spin of J∼ 25ħ and an excitation energy of about E
x∼ 10 MeV. The observation of a positive parity E2 cascade based on the 9/2+ isomeric level is suggestive of collective behaviour in this nucleus up to high spins. Spherical shell model (within restricted
model space) and Cranked shell model calculations were performed to obtain an insight into the observed level structure. The
new collective band observed up to a spin of J∼ 25ħ is suggested to be based on (πg
9/2
3) ⊗ (νg
7/2
2) quasi-particle excitations.
Received: 12 July 1999 / Revised version: 14 September 1999 相似文献
2.
A. Nowak W. Urban M. Rejmund J.L. Durell M.J. Leddy M.A. Jones W.R. Phillips A.G. Smith B.J. Varley I. Ahmad L.R. Morss M. Bentaleb E. Lubkiewicz N. Schulz 《The European Physical Journal A - Hadrons and Nuclei》1998,3(2):111-113
Neutron-rich, N=84 nuclei from the 132Sn region, populated in spontaneous fission of 248Cm, have been studied with EUROGAM 2. Excited states and their spins and parities in the 136Te nucleus were established up to 17ħ. OXBASH code calculations support the experimental identification of maximum aligned
configurations in 136Te. Empirical shell model calculations for the Iπ= 14+ level in 136Te indicate that the adopted mass of the 134Te nucleus should be lowered by 200(80) keV.
Received: 3 August 1998 相似文献
3.
Yu.N. Lobach A.D. Efimov A.A. Pasternak 《The European Physical Journal A - Hadrons and Nuclei》1999,6(2):131-140
Lifetimes of excited states in 110Cd have been measured by the Doppler shift attenuation method in the reaction (α,2nγ) at E
α= 25 MeV. Lifetime values for 8 states and lifetime limits for 3 states were obtained. The band structures of 110Cd have been interpreted in terms of a modified version of the interacting boson model (IBM + 2 q.p.). The calculations explain
well the excitation energies and electromagnetic transition probabilities up to J
π= 16+, except for the 10+
1 state. The structural features are discussed in terms of collective and two quasiparticle excitations.
Received: 20 March 1999 / Revised version: 28 May 1999 相似文献
4.
Ts. Venkova M.-G. Porquet I. Deloncle B.J.P. Gall H. De Witte P. Petkov A. Bauchet T. Kutsarova E. Gueorgieva J. Duprat C. Gautherin F. Hoellinger R. Lucas A. Minkova N. Schulz H. Sergolle E.A. Stefanova A. Wilson 《The European Physical Journal A - Hadrons and Nuclei》1999,6(4):405-413
The 107,109Rh nuclei have been produced as fission fragments following the fusion reaction 28Si +176Yb at 145 MeV bombarding energy and studied with the Eurogam2 array. In both nuclei three new rotational bands with the odd
proton occupying the πg9/2, πp1/2 and π(g7/2/d5/2) sub-shells have been observed. In 107Rh, two other bands involving strong M1 transitions have been identified at excitation energy larger than 2 MeV. They can
be interpreted in terms of three quasiparticle excitations. In addition new structures consisting of four transitions, built
on states located at low excitation energy (680 keV in 107Rh and 642 keV in 109Rh), point out the importance of triaxial deformation in these two isotopes.
Received: 1 September 1999 相似文献
5.
Xie Yuanxiang Xu Shuwei Li Zhankui Yu Yong Pan Qiangyan Wang Chunfang Zhang Tianmei 《The European Physical Journal A - Hadrons and Nuclei》1999,5(3):239-241
Excited levels in 133Sn and 134Sb, populated in spontaneous fission of 248Cm, were studied by means of prompt-γ spectroscopy, using the EUROGAM 2 multidetector array. The neutron i
13/2 single-particle energy has been determined for the first time in the 132Sn region. The energy of the h
9/2 neutron level, proposed previously, has been confirmed.
Received: 13 January 1999 / Revised version: 22 March 1999 相似文献
6.
K. Jessen W. Andrejtscheff M. Bergström P. von Brentano A. Dewald B. Herskind H. Meise C. Schumacher G. Sletten O. Stuch D. Weißhaar I. Wiedenhöver J. Wrzesinski 《The European Physical Journal A - Hadrons and Nuclei》1999,4(1):9-10
A new high-spin isomer in 145Sm was observed by in-beam γ-ray spectroscopy with the reaction 122Sn(27Al,3np) at 127 MeV performed at the Nordball multi-detector array in Roskilde. The excitation energy of the isomer was determined
to be E
x= 11147 keV, and using the generalized centroid-shift method its half-life was found to be T
1/2= (7.4 ± 1.0) ns.
Received: 23 October 1998 相似文献
7.
F. Hoellinger N. Schulz S. Courtin B.J.P. Gall M.-G. Porquet I. Deloncle A. Wilson T. Kutsarova A. Minkova J. Duprat H. Sergolle C. Gautherin R. Lucas 《The European Physical Journal A - Hadrons and Nuclei》1999,4(4):319-321
High-spin states have been studied in 101Tc produced as a fission fragment in the reaction 176Yb +28Si at 145 MeV. Gamma rays were detected with the EUROGAM2 array. The level scheme of 101Tc has been extended up to 4.2 MeV excitation energy and several band structures are observed. Configurations are assigned
to two new bands on the basis of their behaviour and of cranked Hartree-Fock-Bogolyubov calculations.
Received: 4 January 1999 相似文献
8.
E.S. Paul A.J. Boston S. Courtin P.J. Dagnall J.L. Durell C. Finck B. Gall B. Haas F. Haas F. Hannachi F. Hoellinger J.C. Lisle A. Lopez-Martens J.C. Merdinger N. Rowley H.C. Scraggs O. Stezowski B.J. Varley J.P. Vivien 《The European Physical Journal A - Hadrons and Nuclei》2000,7(4):449-450
The low-spin band structure of neutron-deficient 115
54Xe has been studied following a low-energy (212.3 MeV) 60Ni(58Ni,2pnγ) reaction performed at IReS, Strasbourg, with the Garel+ spectrometer. The relative excitation energies of νh11/2 (isomeric), νg7/2, and νd5/2 bandheads have been established.
Received: 23 March 2000 相似文献
9.
C.-B. Moon T. Komatsubara T. Shizuma K. Uchiyama Y. Sasaki K. Furuno 《The European Physical Journal A - Hadrons and Nuclei》1999,4(2):107-109
High-spin states in 121Xe have been studied via the 109Ag (16O, p3n) 121Xe reaction at a beam energy of 80 MeV. Several rotational bands based on one- and three-quasiparticle excitations have been
established. Among them, an unfavoured yrare rotational band with unfavoured signature has been newly identified.
Received: 19 November 1998 相似文献
10.
K. Jessen M. Bergström P. von Brentano A. Dewald B. Herskind H. Meise C. Schumacher G. Sletten O. Stuck D. Weißhaar I. Wiedenhöver J. Wrzesinski 《The European Physical Journal A - Hadrons and Nuclei》1998,2(2):113-114
An in-beam experiment with the reaction 122Sn(27Al,4np) at 127 MeV was performed at the Nordball multi-detector array in Roskilde. It provided evidence for a new high-spin
isomer in 144Sm. This isomer with T
1/2= (2.6 ± 0.5) ns at an excitation energy E
x= 9232 keV seems to belong to a family of isomers of similar configuration in neighbouring N= 82 nuclei.
Received: 16 November 1997 相似文献
11.
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
12.
M. Rejmund K.H. Maier R. Broda B. Fornal M. Lach J. Wrzesiński J. Blomqvist A. Gadea J. Gerl M. Górska H. Grawe M. Kaspar H. Schaffner C. Schlegel R. Schubart H.J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):261-266
High spin states in nuclei around 208Pb were populated in deep inelastic collisions of 76Ge, 136Xe, and 208Pb projectiles with 208Pb targets at beam energies about 12% above the Coulomb barrier. New states in 209Pb were found by measuring γ-γ-coincidences. They are interpreted as the yrast states that originate from the coupling of
one neutron to the lowest excitations of the 208Pb core. The results are discussed in the frame of the shell model.
Received: 22 November 1997 相似文献
13.
D.C. Radford C. Baktash A. Galindo-Uribarri C.J. Gross T.A. Lewis P.E. Mueller P.A. Hausladen D. Shapira D.W. Stracener C.-H. Yu B. Fuentes E. Padilla D.J. Hartley C.J. Barton M. Caprio N.V. Zamfir 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):171-173
The Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory has recently produced the world's first post-accelerated
beams of heavy neutron-rich nuclei. The first experiments with these beam are described, and the results discussed. B(E2;0+ → 2+) values for neutron-rich 126,128Sn and 132,134,136Te isotopes have been measured by Coulomb excitation in inverse kinematics. The results for 132Te and 134Te (N = 80, 82) show excellent agreement with systematics of lighter Te isotopes, but the B(E2) value for 136Te (N = 84) is unexpectedly small. Single-neutron transfer reactions with a 134Te beam on natBe and 13C targets at energies just above the Coulomb barrier have also been studied.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: radford@mail.phy.ornl.gov 相似文献
14.
J. Timár A. Gizon P. Paris J. Genevey J. Gizon F. Hannachi C.F. Liang A. Lopez-Martens J.C. Merdinger B.M. Nyakó B. Weiss L. Zolnai 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):7-10
High spin states of 126La have been populated using the reaction 116Sn+14N at 68 MeV. γ-rays and conversion electrons were detected with the GAREL array. Multipolarities of the lowest-lying in-band
dipole transitions have been determined from the deduced internal conversion coefficients. Experimental B(M1)/B(E2) ratios
have been derived for the bands and compared with calculated values using the D?nau-Frauendorf geometrical model. Configurations
are proposed for the bands comparing them with cranked shell model calculations and on the basis of the measured B(M1)/B(E2)
ratios. The β-decay of 126La has also been revisited. The population of the 126Ba levels gives a probable spin value of five for the decaying high-spin 126La state with T
1/2≈ 64 s which may indicate a signature inversion in the πh11/2νh11/2 band.
Received: 12 October 1999 相似文献
15.
Z. Liu X. Sun X. Zhou X. Lei Y. Guo Y. Zhang X. Chen H. Jin Y. Luo S.X. Wen C.X. Yang G.J. Yuan G.S. Li X.A. Liu W.D. Luo Y.S. Chen 《The European Physical Journal A - Hadrons and Nuclei》1998,1(2):125-135
High-spin states of 117Xe were investigated by means of in-beam γ-ray spectroscopic techniques via the reaction of 28Si bombarding a 92Mo target at beam energies of 100-120 MeV. A positive-parity rotational band decaying into the yrast negative-parity band
by a series of enhanced E1 transitions was observed for the first time, implying the existence of octupole correlations in
117Xe. The B(E1) values increase with spin. The νd5/2 band was firmly established up to 27/2+ and the B(M1)/B(E2) ratios were extracted from the relative intensities of γ-rays in this band. The previously known νh11/2 and νg7/2 [413]5/2+α=−1/2 bands were confirmed and extended up to high spins and two bandcrossings are observed in the latter at ħω=0.33 and
0.44 MeV, respectively. The bandcrossings and configurations of these bands are discussed by TRS and CSM calculations. In
a γ–γ–t measurement, the 11/2− and 7/2− levels were identified as two isomers with half-lives of 59.4±20 ns and 16.5±8.0 ns, respectively.
Received: 17 June 1997 / Revised version: 29 September 1997 相似文献
16.
T. Kautzsch W.B. Walters M. Hannawald K.-L. Kratz V.I. Mishin V.N. Fedoseyev W. Böhmer Y. Jading P. Van Duppen B. Pfeiffer A. Wöhr P. Möller I. Klöckl V. Sebastian U. Köster M. Koizumi J. Lettry H.L. Ravn the ISOLDE Collaboration 《The European Physical Journal A - Hadrons and Nuclei》2000,9(2):201-206
A chemically selective laser ion source has been used in a β-decay study of heavy Ag isotopes into even-even Cd nuclides.
Gamma-spectroscopic techniques in time-resolving event-by-event and multiscaling modes have permitted the identification of
the first 2+ and 4+ levels in 126Cd78, 128Cd80, and tentatively the 2+ state in 130Cd82. From a comparison of these new states in 48Cd with the E(2+) and E(4+)/E(2+) level systematics of 46Pd and 52Te isotopes and several recent model predictions, possible evidence for a weakening of the spherical N = 82 neutron-shell below double-magic 132Sn is obtained.
Received: 13 July 2000 / Accepted: 12 October 2000 相似文献
17.
M.B. Smith R. Chapman J.F.C. Cocks O. Dorvaux K. Helariutta P.M. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen P. Kuusiniemi Y. Le Coz M. Leino D.J. Middleton M. Muikku P. Nieminen P. Rahkila A. Savelius K.-M. Spohr 《The European Physical Journal A - Hadrons and Nuclei》1999,5(1):43-47
Excited states in the Z= 85 nucleus 197At have been identified for the first time using the recoil-decay-tagging (RDT) technique. The excitation energy of these
states is found to be consistent with the systematics of neutron-deficient astatine nuclei and with theoretical calculations
indicating that the nucleus may be deformed in its ground state.
Received: 8 January 1999 相似文献
18.
19.
W. Urban N. Schulz M. Bentaleb E. Lubkiewicz J. L. Durell M. J. Leddy M. A. Jones W. R. Phillips A. G. Smith B. J. Varley I. Ahmad L. R. Morss 《The European Physical Journal A - Hadrons and Nuclei》2000,8(1):5-7
Excited levels in 141Xe, populated in spontaneous fission of 248Cm, were studied by means of prompt -ray spectroscopy, using the EUROGAMM2 array. Level scheme of 141Xe obtained in this work shows patterns characteristic of simplex symmetry with s=+i and s=-i bands present but low value of D0 moment indicates that octupole correlations in Xe isotopes are systematically lower than in Ba nuclei.
Received: 9 March 2000 / Accepted: 4 May 2000 相似文献
20.
GCM analysis of the collective properties of lead isotopes with exact projection on particle numbers
P.-H. Heenen A. Valor M. Bender P. Bonche H. Flocard 《The European Physical Journal A - Hadrons and Nuclei》2001,11(4):393-402
We present a microscopic analysis of the collective behaviour of the lead isotopes in the vicinity of 208Pb. In this study, we rely on a coherent approach based on the Generator Coordinate Method (GCM) including exact projection
on N and Z numbers within a collective space generated by means of the constrained Hartree-Fock BCS method. With the same Hamiltonian
used in HF + BCS calculations, we have performed a comprehensive study including monopole, quadrupole and octupole excitations
as well as pairing vibrations. We find that, for the considered nuclei, the collective modes which modify the most the conclusions
drawn from the mean-field theory are the octupole and pairing vibrations.
Received: 31 May 2001 / Accepted: 23 August 2001 相似文献