共查询到20条相似文献,搜索用时 168 毫秒
1.
K. Van de Vel A.N. Andreyev R.D. Page H. Kettunen P.T. Greenlees P. Jones R. Julin S. Juutinen H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino M. Muikku P. Nieminen P. Rahkila J. Uusitalo K. Eskola A. Hürstel M. Huyse Y. Le Coz M.B. Smith P. Van Duppen R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):167-171
Gamma rays from excited states of 190Po have been observed using the Jurosphere Ge-detector array coupled to the RITU gas-filled separator. They were associated
with a collective band which from spin 4 onwards resembles the prolate rotational bands known in the isotones 188Pb and 186Hg. This indicates that in 190Po the prolate configuration becomes yrast above I = 2. The experimental results are interpreted in a two-band mixing calculation and are in agreement with α-decay data and
potential energy surface calculations.
Received: 10 January 2003 / Accepted: 19 February 2003 / Published online: 7 May 2003 相似文献
2.
L-L. Andersson D. Rudolph J. Ekman C. Fahlander E. K. Johansson R. du Rietz C. J. Gross P. A. Hausladen D. C. Radford G. Hammond 《The European Physical Journal A - Hadrons and Nuclei》2006,30(2):381-390
The 61
30Zn31 isotope has been produced at the Oak Ridge National Laboratory in the fusion-evaporation reaction 40Ca(24Mg, 2pn)61Zn at 104MeV. The experimental set-up allowed γ-rays to be detected in the CLARION Ge detector array in coincidence with the
detection of recoiling nuclei in the focal plane at the end of the recoil mass spectrometer. This provides a unique identification
of γ-rays belonging to 61Zn. The excited states have been explored by means of recoil- γγ coincidences, and the resulting decay scheme comprises almost
70 transitions. The data reveal numerous non-yrast states and suggest a revised spin and parity assignment for a previously
observed superdeformed band. The resulting decay scheme is compared to predictions from different sets of large-scale shell
model calculations. 相似文献
3.
Ts. Venkova W. Gast R. M. Lieder D. Bazzacco G. de Angelis E. O. Lieder A. A. Pasternak R. Menegazzo S. Lunardi C. Rossi Alvarez C. Ur T. Martinez M. Axiotis D. Napoli W. Urban T. Rzaca-Urban S. Frauendorf 《The European Physical Journal A - Hadrons and Nuclei》2005,26(1):19-24
High-spin states in the neutron-rich nuclei 172,173Yb have been populated in a 170Er(7Li,(p,d,t)xn) incomplete-fusion reaction and the emitted γ-radiation was detected with the GASP array. The signature partners of the
7/2+[633] rotational band of the odd-N 173Yb isotope have been newly established and were observed up to spin values of (45/2+) and (43/2+), respectively. The ground-state band of the even-even nucleus 172Yb has been observed up to a spin value of (22+). No band crossings were found in these bands. To explain this observation, it is proposed that the static pair field is
absent, considering that the neutron odd-even mass differences reach for these nuclei very small values and that the band
crossing is absent in cranked shell modell calculations without pairing. The results indicate, however, that strong dynamic
correlations are still present. 相似文献
4.
K. Helariutta J.F.C. Cocks T. Enqvist P.T. Greenlees P. Jones R. Julin S. Juutinen P. Jämsen H. Kankaanpää H. Kettunen P. Kuusiniemi M. Leino M. Muikku M. Piiparinen P. Rahkila A. Savelius W.H. Trzaska S. Törmänen J. Uusitalo R.G. Allatt P.A. Butler R.D. Page M. Kapusta 《The European Physical Journal A - Hadrons and Nuclei》1999,6(3):289-302
Prompt and delayed γ-rays have been observed from very neutron deficient 192–195Po nuclei by using the recoil-decay tagging (RDT) and recoil gating techniques. The yrast levels up to the (10+) state in the 192Po were identified for the first time. Comprehensive data for 194Po rendered it possible to extend the yrast line and to observe several positive and negative parity non-yrast states. In
the odd-mass isotopes 193Po and 195Po, favoured and unfavoured states on top of the 13/2+ state have been identified. The results are discussed within the simple vibrator and rotor pictures as well as in the framework
of coexisting spherical and deformed-intruder structures.
Received: 5 July 1999 / Revised version: 7 September 1999 相似文献
5.
R. Krücken S.J. Asztalos R.M. Clark M.A. Deleplanque R.M. Diamond P. Fallon I.Y. Lee A.O. Macchiavelli G.J. Schmid F.S. Stephens K. Vetter Jing-Ye Zhang 《The European Physical Journal A - Hadrons and Nuclei》2001,10(2):151-155
High-spin states in 112Pd were studied using prompt γ-ray spectroscopy with Gammasphere following heavy-ion-induced fission in the reaction 18O + 208Pb at 91 MeV. A new 8+ level at 2638 keV was discovered with transitions connecting it to the yrast band and the quasi-gamma band. The three, now
established, closely spaced 8+ states indicate a mixing between the ground-state band, s-band, and quasi-gamma band. Several high-spin structures with likely negative parity have been extended to higher spin and
it is proposed that they are based on the νh
11/2(g
7/2
d
5/2) and νh
11/2(s
1/2
d
3/2) configurations.
Received: 28 November 2000 / Accepted: 8 February 2001 相似文献
6.
K. Singh S. Sihotra S. S. Malik J. Goswamy D. Mehta N. Singh R. Kumar R. P. Singh S. Muralithar E. S. Paul J. A. Sheikh C. R. Praharaj 《The European Physical Journal A - Hadrons and Nuclei》2006,27(3):321-324
The collective band structures of the 125Cs nucleus have been investigated by in-beam γ-ray spectroscopic techniques following the 110Pd ( 19F, 4n) reaction at 75MeV. The previously known level scheme, with rotational bands built on πg7/2, πg9/2 and πh11/2 orbitals, has been extended and evolves into bands involving rotationally aligned ν(h11/2)2 and π(h11/2)2 quasiparticles. A strongly coupled band has been reassigned a high-K πh11/2 ⊗ νg7/2 ⊗ νh11/2 three-quasiparticle configuration and a new side band likely to be its chiral partner has been identified. Configurations
assigned to various bands are discussed in the framework of Principal/Tilted Axis Cranking (PAC/TAC) model calculations. 相似文献
7.
C.M. Petrache G. Lo Bianco D. Bazzacco Th. Kröll S. Lunardi R. Menegazzo M. Nespolo P. Pavan C. Rossi Alvarez M. Axiotis G. de Angelis E. Farnea N. Marginean D.R. Napoli N. Blasi 《The European Physical Journal A - Hadrons and Nuclei》2001,12(2):139-141
The even-even nucleus 128Nd was studied via in-beam γ-ray spectroscopy using the 40Ca + 82Mo reaction at 190 MeV. Two new bands were observed besides the yrast one, that has been extended up to spin 34+. Configurations were assigned to the three bands by analysing their rotational properties and by comparison with the neighboring
even-even nuclei.
Received: 18 July 2001 / Accepted: 25 October 2001 相似文献
8.
M. Weiszflog G. de Angelis A. Axelsson D. Bazzacco F. Becker M. De Poli J. Eberth C. Fahlander A. Gadea S. Lunardi D.R. Napoli J. Nyberg C. Rossi Alvarez B. Rubio D. Rudolph S. Skoda H.G. Thomas R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》2001,11(1):25-38
High-spin states in the nuclei 63Ga and 65Ga were studied following the reaction 32S + 40Ca at a reaction energy of 125 MeV and using the GASP γ-ray spectrometer in combination with the ISIS charged-particle detector
system. In addition to low-lying negative-parity states with single-particle character, rotational-like cascades built on
the 9/2+ and 19/2- states have been observed in both nuclei. Sidebands with negative parity in 63Ga and positive parity in 65Ga could be established. The experimental results are compared with Total Routhian Surface calculations which describe the
nuclei as moderately deformed (β2≈ 0.25) and γ soft at low rotational frequencies. The highest experimentally observed positive-parity state in 65Ga (41/2+) is in good agreement with the calculated crossing of the collective band with a non-collective one terminating at this spin.
Received: 20 December 2000 / Accepted: 2 May 2001 相似文献
9.
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
10.
T. Shizuma Y. Toh M. Oshima M. Sugawara M. Matsuda T. Hayakawa M. Koizumi A. Osa Y.H. Zhang Z. Liu 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):159-165
Excited states in 187Re populated by inelastic scattering of a 500 MeV 82Se beam have been studied by means of in-beam γ-ray spectroscopy. Levels built on the 5/2+[402] and 9/2-[514] one-quasiparticle states were measured up to I
π = (21/2+) and (21/2-), respectively. In addition, several new levels including an isomer at 1682 keV with a half-life of 114(23) ns have been
found. Quasiparticle configurations of the levels and the transition rates are discussed.
Received: 12 December 2002 / Accepted: 13 March 2003 / Published online: 13 May 2003 相似文献
11.
S. Eeckhaudt P. T. Greenlees N. Amzal J. E. Bastin E. Bouchez P. A. Butler A. Chatillon K. Eskola J. Gerl T. Grahn A. Görgen R. -D. Herzberg F. P. Hessberger A. Hürstel P. J. C. Ikin G. D. Jones P. Jones R. Julin S. Juutinen H. Kettunen T. L. Khoo W. Korten P. Kuusiniemi Y. Le Coz M. Leino A. -P. Leppänen P. Nieminen J. Pakarinen J. Perkowski A. Pritchard P. Reiter P. Rahkila C. Scholey Ch. Theisen J. Uusitalo K. Van de Vel J. Wilson 《The European Physical Journal A - Hadrons and Nuclei》2005,26(2):227-232
Evidence for the decay of non-yrast states in 254No has been observed for the first time in an experiment performed at the University of Jyv?skyl?. The experiment employed
the JUROGAM array of germanium detectors coupled to the gas-filled recoil separator RITU and the focal-plane spectrometer
GREAT. The ground-state rotational band has been tentatively extended up to a spin of 24ℏ and has a smoothly behaving dynamical
moment of inertia. It is speculated that the observation of high-energy γ-rays is due to the decay of a K = 3 band-head state. 相似文献
12.
F. Ibrahim J. Genevey E. Cottereau A. Gizon A. Knipper F. Le Blanc G. Marguier J. Obert J. Oms J.C. Putaux B. Roussière J. Sauvage A. Wojtasiewicz 《The European Physical Journal A - Hadrons and Nuclei》2001,10(2):139-143
Low-lying states in the odd-odd light gold isotope 182Au have been populated by the β+/EC decay of the 182Hg nuclei. Level energies, spin and parity values were determined using on-line γ-ray and e- spectroscopy measurements. No isomeric state with a long half-life was found in the 182Au nucleus. Spin and parity I
π = 2+ can be very likely assigned to the 182Au ground state.
Received: 19 December 2000 / Accepted: 28 February 2001 相似文献
13.
T. Bäck B. Cederwall K. Lagergren R. Wyss A. Johnson P. Greenlees D. Jenkins P. Jones D.T. Joss R. Julin S. Juutinen A. Keenan H. Kettunen P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku P. Nieminen J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2003,17(1):1-5
The decay out of the πh
11/2νh
11/2 band to the known low-energy levels in 132La was studied using the reaction 100Mo + 36S at 160 MeV beam energy. The low-energy level scheme has been further developed and unambiguous spin and parity values have
been assigned to the levels connecting the band to the 6- isomeric state. According to the new level scheme the spins in the πh
11/2νh
11/2 band are shifted up by one unit compared to the earlier tentative experimental values. The obtained new spins prove the existence
of signature inversion in 132La and give further support to the spin assignments made for the πh
11/2νh
11/2 bands in the neighbouring odd-odd La isotopes from level energy systematics.
Received: 7 May 2002 / Accepted: 31 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: timar@atomki.hu
RID="b"
ID="b"Present address: Dipartimento di Matematica e Fisica, Università di Camerino, via Madonna delle Carceri, I-62032 Camerino, Italy.
Communicated by J. ?yst? 相似文献
14.
G. Lhersonneau B. Pfeiffer J. Alstad P. Dendooven K. Eberhardt S. Hankonen I. Klöckl K.-L. Kratz A. Nähler R. Malmbeck J.P. Omtvedt H. Penttilä S. Schoedder G. Skarnemark N. Trautmann J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):285-297
The decay of 111Ru obtained from fast on-line chemical and mass separation has been investigated by β-γ-t and γ-γ coincidence techniques. Earlier spin and parity assignments of 111Rh levels based on extrapolations of level systematics are confirmed. In particular, the K=1/2 intruder band is supported
by the hindrance of E2 transitions between deformed and spherical states and enhancement of intraband E2 transitions. The
excitation energies of intruder band members in Rh isotopes show a minimum at 109Rh64, with two neutrons less than 111Rh at the N=66 midshell. This trend, which differs from the one in the higher-Z neighbouring elements Ag and Cd with minima
at N=66, follows the evolution of deformation observed in the lower-Z elements Ru and Mo.
Received: 25 June 1997 / Revised version: 10 September 1997 相似文献
15.
Ch. Hinke R. Krücken R. F Casten V. Werner N. V. Zamfir 《The European Physical Journal A - Hadrons and Nuclei》2006,30(2):357-367
The evolution of the structure of the gamma-vibrational band head 2+
γ in well-deformed rare-earth nuclei is studied within the framework of RPA calculations using a quasiboson approximation based
on the Nilsson model. The obtained evolution of the quasiparticle structure of the gamma-vibrational band head is shown to
correlate well with the evolution of the same nuclei within the IBA symmetry triangle when described in the extended consistent-Q formalism. An empirical relation is presented that links the IBA parameter χ with the quasiparticle structure of the gamma-vibrational
band head. 相似文献
16.
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
17.
X. H. Zhou L. Ma Y. B. Xing Y. H. Zhang Y. X. Guo X. G. Lei C. Y. Xie M. Oshima Y. Toh M. Koizumi A. Osa Y. Hatsukawa M. Sugawara M. M. Ndontchueng 《The European Physical Journal A - Hadrons and Nuclei》2006,28(3):271-275
Excited states in 188Tl have been studied experimentally using the 157Gd (35Cl, 4n) reaction at a beam energy of 170MeV. A rotational band built on the πh
9/2 ⊗ νi
13/2 configuration with oblate deformation has been established for 188Tl. Based on the structure systematics of the oblate πh
9/2 ⊗ νi
13/2 bands in the heavier odd-odd Tl nuclei, we have tentatively proposed spin values for the new band in 188Tl. The πh
9/2 ⊗ νi
13/2 oblate band in 188Tl shows low-spin signature inversion, and it can be interpreted qualitatively by the two-quasiparticle plus rotor model including
a J-dependent p-n residual interaction. 相似文献
18.
Y.H. Zhang S.Q. Zhang W.X. Huang X.H. Zhou X.C. Feng X. Xu X.G. Lei Y.X. Guo S.F. Zhu J.J. He Z. Liu S.J. Wang Y.X. Luo 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):19-22
An effort has been made to search for the decoupled bands in odd-odd 174Re via the 159Tb(20Ne,5n γ)174Re reaction through excitation functions, K x-γ and γ-γ coincidence measurements. The doubly decoupled band and the semidecoupled
one have been found in this work. Their quasiparticle configurations are proposed to be π1/2−[541] ⊗ν1/2−[521] and π1/2−[541] ⊗νi
13/2, respectively, according to the characteristics of band structures in this mass region. Another band with strongly coupled
character is also reported.
Received: 23 November 1999 / Revised version: 5 January 2000 相似文献
19.
I. Piqueras M.J.G. Borge Ph. Dessagne J. Giovinazzo A. Huck A. Jokinen A. Knipper C. Longour G. Marguier M. Ramdhane V. Rauch O. Tengblad G. Walter Ch. Miehé 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):313-329
The beta-decay of the N = Z, even-even nucleus 72Kr has been studied at the ISOLDE PSB facility at CERN. Measurements of βγ and βγγ coincidences have enriched the decay scheme
of the daughter nucleus 72Br with 27 new low spin levels. A more precise half-life of T
1/2 = 17.1(2) s has been determined. Strong feeding to the 72Br ground state is established yielding an unambiguous J
π = 1+ assignment for this state. Candidates for the 72Br g.s. wave function are discussed in the framework of a self-consistent deformed mean-field calculation with SG2 Skyrme
force and pairing correlations. A search for beta-delayed particle emission was made and an upper limit of 10-6 for this decay branch obtained. The cumulated experimental level density of 1+ states has been fitted with the constant temperature formula. The comparison indicates that most likely all 1+ levels up to 1.2 MeV have been observed in this investigation. The corresponding nearest-neighbour level spacing does not
follow a Poisson distribution. The Gamow-Teller strength distribution is compared, in terms of nuclear deformation, with different
calculations made in the framework of the quasiparticle random phase approximation.
Received: 7 February 2002 / Accepted: 31 October 2002 / Published online: 6 March 2003
RID="a"
ID="a"e-mail: borge@pinar2.csic.es
RID="b"
ID="b"Present address: Centre d' Etudes Nucléaires de Bordeaux-Gradignan, Le Haut Vigneau, F-33175 Gradignan Cedex, France.
RID="c"
ID="c"Present address: University Mentouri, 25000 Constantine, Algeria.
Communicated by J. ?yst? 相似文献
20.
T. Steinhardt J. Eberth I. Ragnarsson 《The European Physical Journal A - Hadrons and Nuclei》2007,33(4):303-306
Based on the γ -spectroscopic analysis of G.N. Sylvan et al., configuration-dependent cranked Nilsson-Strutinsky calculations have been performed. They describe the nucleus 77Kr globally in good agreement with the experimental findings and the expectations derived from single-particle orbitals in
a deformed potential. Within these calculations, the unambiguous assignment of a configuration with three protons and five
neutrons in the g
9/2 shell to the high-spin Yrast states of negative parity indicates that the nucleus 77Kr has stable triaxial deformation and rotates about the intermediate axis. This not only disproves the recent interpretation
of an occupation of the d
5/2 orbital being responsible for the strong deformation in this band, but also represents one of the first examples in this
mass region for such a rotation. 相似文献