共查询到20条相似文献,搜索用时 15 毫秒
1.
A.N. Andreyev D. Ackermann P. Cagarda J. Gerl F. Heßberger S. Hofmann M. Huyse A. Keenan H. Kettunen A. Kleinböhl A. Lavrentiev M. Leino B. Lommel M. Matos G. Münzenberg C. Moore C.D. O'Leary R.D. Page S. Reshitko S. Saro C. Schlegel H. Schaffner M. Taylor P. Van Duppen L. Weissman R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》1999,6(4):381-385
New neutron-deficient isotopes 188,189Po have been produced in the complete fusion reaction of 52Cr ions with a 142Nd target at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the
basis of α-γ and α-conversion electron coincidence measurements and of α-α position and time correlations. In 189Po a ground state to ground state α decay with Eα1= 7540(20) keV, T1/2= 5(1) ms and two fine structure α-decays at Eα2= 7264(15) keV and Eα3= 7316(15) keV have been observed. In 188Po (T1/2= 400+200
−150μs) a ground state to ground state α decay at Eα= 7915(25) keV and a fine structure α decay at Eα= 7350(40) keV have been found. Improved data on the α-decay of 189Bi were obtained.
Received: 15 October 1999 相似文献
2.
M. Bender T. Cornelius G.A. Lalazissis J.A. Maruhn W. Nazarewicz P.-G. Reinhard 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):23-28
Recent mass measurements show a substantial weakening of the binding-energy difference δ2p(Z, N) = E(Z - 2, N) - 2E(Z, N) + E(Z + 2, N) in the neutron-deficient Pb isotopes. As δ2p is often attributed to the size of the proton magic gap, it might be speculated that reduction in δ2p is related to a weakening of the spherical Z = 82 shell. We demonstrate that the observed trend is described quantitatively by self-consistent mean-field models in terms
of deformed ground states of Hg and Po isotopes.
Received: 25 October 2001 / Accepted: 28 February 2002 相似文献
3.
J. Benlliure T. Kurtukian-Nieto L. Audouin B. Blank F. Becker E. Casarejos D. Cortina M. Fernández-Ordóñez J. Giovinazzo D. Henzlova B. Jurado J. Pereira F. Rejmund K.-H. Schmidt O. Yordanov 《The European physical journal. Special topics》2007,150(1):309-310
The production of heavy neutron-rich nuclei is investigated using cold-fragmentation reactions.
More than 25 new heavy neutron-rich nuclei were produced in the fragmentation of 208Pb projectiles at 1 A GeV impinging a
beryllium target. The precise measurement of their production cross sections enables to benchmark the predictive power of
different
model calculations and make reliable predictions of the production rates expected in future radioactive beam facilities. 相似文献
4.
J.M. Chatterjee S. Basu-Roy S.S. Ghugre S. Chattopadhyay R.P. Singh G.O. Rodrigues R.K. Chattopadhyay R.K. Bhowmik 《The European Physical Journal A - Hadrons and Nuclei》1998,1(1):55-59
A search for new isomers of nanosecond lifetimes were carried out in 153Eu via the 150Nd(7Li,xnγ) reaction. The single particle angular momentum alignment and dynamical moment of inertia estimated from the experimental
data indicate a configuration change at rotational energy ħω∼ 0.30 MeV. A decrease of B(E2) values is also observed at the
same frequency. An isomeric level is identified at an excitation energy of 3100 keV (Jπ=35/2−) which corresponds to this frequency. The lifetime of the level is found to be 8.6 ± 1.3 nanosecond.
Received: 22 April 1997 / Revised version: 26 September 1997 相似文献
5.
C. Wheldon P.M. Walker R. D'Alarcao P. Chowdhury C.J. Pearson E.H. Seabury I. Ahmad M.P. Carpenter D.M. Cullen G. Hackman R.V.F. Janssens T.L. Khoo D. Nisius P. Reiter 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):353-355
A t
1/2 > 1 ms, high-K isomeric state feeding a strongly coupled rotational band has been identified following the deep inelastic
reaction 238
92U +186
74W at 1600 MeV. Examination of γ-ray and X-ray data combined with a g-factor analysis derived from in-band branching ratios
suggests the assignment of the new states to the neutron-rich nucleus 185
73Ta.
Received: 11 May 1999 相似文献
6.
T. Shizuma K. Furuno K. Hata H. Ishiyama T. Jumatsu M. Kato T. Komatsubara K. Matsuura Y. Sasaki K. Uchiyama T. Hayakawa 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):245-246
High-spin states in 183Os have been studied by means of in-beam γ-ray spectroscopy. Two isomers with I
π= ((43/2)−) and (43/2)+ have been identified at excitation energies of E
x
= 5.068 and 5.168 MeV. The half-lives are determined as T
1/2= 27 ± 3 and 24 ± 2 ns.
Received: 22 December 1997 相似文献
7.
S.K. Katoch S.L. Gupta S.C. Pancholi D. Mehta S. Malik G. Shanker L. Chaturvedi R.K. Bhowmik 《The European Physical Journal A - Hadrons and Nuclei》1999,4(4):307-309
High-spin states in the odd-odd 168Lu nucleus, populated in the 154Sm(19F,5n) reaction at a beam energy of 96 MeV, were investigated using in-beam γ-ray spectroscopy techniques. The BC neutron crossing
in the yrast band, based on πg
7/2[404]7/2+⊗νi
13/2[642]5/2+ configuration, occurs at ħω= 0.31 MeV. The two side bands, based on πh
11/2[514]9/2−⊗νi
13/2[642]5/2+ and πh
9/2[541]1/2−⊗νi
13/2[642]5/2+ configurations, show anomalous signature-splitting and signature-inversion in the first one, to occur at ħω= 0.24 MeV. A
moderately delayed BC-crossing is anticipated in the second one.
Received: 15 June 1998 / Revised version: 11 January 1999 相似文献
8.
A. Hürstel M. Rejmund E. Bouchez P.T. Greenlees K. Hauschild S. Juutinen H. Kettunen W. Korten Y. Le Coz P. Nieminen Ch. Theisen A.N. Andreyev F. Becker T. Enqvist P.M. Jones R. Julin H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):329-334
Prompt and delayed gamma-ray spectroscopy of very neutron-deficient bismuth isotopes 187, 189Bi has been performed using the Recoil Decay Tagging (RTD) method. The isomeric i
13/2 states have been identified and their lifetimes have been measured. The systematics of these long-lived M2 isomers has been extended to the proton-unbound isotopes. The general behaviour of single-proton states is discussed within
the systematics and interpreted within the shell-model framework.
Received: 2 May 2002 / Accepted: 3 June 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: wkorten@cea.fr
RID="b"
ID="b"Present address: GANIL, Caen, France.
RID="c"
ID="c"Present address: Radiation and Nuclear Safety Authority, P.O. Box 14, FIN-00881 Helsinki.
Communicated by D. Schwalm 相似文献
9.
M. Lach P. Bednarczyk P.T. Greenlees K. Helariutta P. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen P. Kuusiniemi M. Leino W. Meczyński M. Muikku P. Nieminen P. Rahkila J. Styczeń J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2000,9(3):307-308
The 13/2+ isomeric state in the 199At nucleus has been identified at an excitation energy of 573 keV and its half-life measured to be 580(130) ns using the recoil-decay
tagging technique.
Received: 19 September 2000 / Accepted: 1 November 2000 相似文献
10.
R. Krücken Z. Wang S.J. Asztalos J.A. Becker L.A. Bernstein R.M. Clark M.A. Deleplanque R.M. Diamond P. Fallon N. Fotiades K. Hauschild I.Y. Lee A.O. Macchiavelli G.J. Schmid F.S. Stephens K. Vetter 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):367-370
Lifetimes of states in the two strongest superdeformed (SD) bands in 193Tl were measured using the Doppler-shift attenuation method. The reaction 176Yb(23Na,6n)193Tl at a beam energy of 129 MeV was used and γ-rays were detected by the Gammasphere array. Quadrupole moments of 18.3(10)
eb and 17.4(10) eb were extracted for SD bands 1 and 2, respectively, using the fractional Doppler-shifts of the SD transitions.
The previously reported linking transitions of these SD bands to normal deformed near yrast levels could not be confirmed.
No other candidates for linking transitions could be established.
Received: 27 April 1999 相似文献
11.
M.A. Caprio N.V. Zamfir E.A. McCutchan R.F. Casten Z. Berant H. Amro C.J. Barton C.W. Beausang D.S. Brenner J.R. Cooper R.L. Gill G. Gürdal A.A. Hecht C. Hutter R. Krücken D.A. Meyer J.R. Novak N. Pietralla P.H. Regan J.J. Ressler 《The European Physical Journal A - Hadrons and Nuclei》2003,16(2):177-180
Lifetime measurements for the 2+
1 levels of 162Er and 162Yb were obtained in β+/ɛ decay at the Yale Moving Tape Collector by fast electronic scintillation timing of β+γ coincidences.
Received: 2 September 2002 / Accepted: 1 October 2002 / Published online: 4 February 2003
RID="a"
ID="a"e-mail: mark.caprio@yale.edu
Communicated by J. ?yst? 相似文献
12.
T.R. Saitoh N. Hashimoto G. Sletten R.A. Bark S. Törmänen M. Bergström K. Furuno K. Furutaka G.B. Hagemann T. Hayakawa T. Komatsubara A. Maj S. Mitarai M. Oshima J. Sampson T. Shizuma P.G. Varmette 《The European Physical Journal A - Hadrons and Nuclei》1998,3(3):197-199
High-spin states in 181Ta have been studied via the 176Yb(11B,α2n) reaction at 52 MeV using the PEX array and at 57 MeV using the NORDBALL array, with α-particle detection. The previously
known, Kπ=(7/2)+ ground state band and Kπ=(9/2)− band have been extended to spins (29/2)+ and (31/2)−, respectively. Two new one-quasiparticle bands, the Kπ=(5/2)+ band built on the known (5/2)+ isomer and a Kπ=((1/2)−) band have been observed. Two other rotational bands with three-quasiparticle structure, Kπ=(15/2)− and ((19/2)+ with π(7/2)[404]ν2(1/2)[510](9/2)[624] and π(9/2)[514]ν2(1/2)[510](9/2)[624] configurations, respectively, have been newly observed. The half-life of the Kπ=((19/2)+) bandhead which decays to the head of the (15/2)− band has been measured to be 140(36) ns. However, transitions from the ((19/2)+) state to the (15/2)− band have not been observed.
Received: 26 August 1998 相似文献
13.
14.
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
15.
V. Rizzi G. Viesti D. Bazzacco A. Algora-Pineda D. Appelbe G. de Angelis N. Belcari M. Cinausero M. De Poli T.E. Drake A. Gadea A. Galindo-Uribarri N. Gelli D. Fabris E. Farnea E. Fioretto W. Krolas T. Kroll F. Lucarelli S. Lunardi M. Lunardon T. Martinez R. Menegazzo B.K. Nayak G. Nebbia D.R. Napoli B. Nyakó C. Petrache Zs. Podolyák G. Prete C. Rossi Alvarez A. Samant P. Spolaore C. Ur K. Zuber 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):299-301
The ridge structure with ΔEγ=±30 keV, observed in the past in coincidence with protons emitted in the reaction 187 MeV 37Cl +120Sn and attributed to an hyperdeformed nuclear shape in 152Dy, has been studied in a new experiment performed with the EUROBALL III array. The ridge is now observed in coincidence with
transitions in the yrast superdeformed band of 152Dy but no discrete rotational bands have been identified.
Received: 7 February 2000 相似文献
16.
R. Julin P.T. Greenlees K. Helariutta P. Jones S. Juutinen A.-P. Leppänen H. Kankaanpää A. Keenan H. Kettunen P. Kuusiniemi M. Leino M. Muikku P. Nieminen J. Pakarinen P. Rahkila J. Uusitalo D.T. Joss S.J. Williams D.G. Jenkins N.-S. Kelsall R. Wadsworth K. Hauschild A. Hürstel W. Korten Y. Le Coz A.N. Andreyev P. Van Duppen M. Huyse K. Van de Vel C.J. Moore C.D. O'Leary R.D. Page M.J. Taylor W. Reviol M.B. Smith 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):189-193
The JYFL gas-filled recoil separator RITU, combined with Ge detector arrays and a SACRED magnetic solenoid spectrometer, has
been successfully employed in recoil-decay-tagging (RDT) experiments in order to probe structures of very neutron-deficient
heavy nuclei. The present contribution focuses on the light Pb region where the new data extend the systematics of shape-coexisting
yrast states towards the proton dripline. Similarities between band structures and their relation to possible multi-particle
multi-hole intruder excitations will be discussed.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: rauno.julin@phys.jyu.fi 相似文献
17.
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
18.
C. Foin F. Farget A. Gizon D. Santos D. Barnéoud J. Genevey J. Gizon P. Paris M. Ashgar A. Płochocki 《The European Physical Journal A - Hadrons and Nuclei》2000,7(2):149-153
The high-spin level structure of the 153Er nucleus has been reinvestigated by in-beam γ-ray and electron spectroscopy with (14N,pxn) reaction. Excitation energies, spin and parity assignments are unambiguously established for the two lowest isomers
T
1/2≃ 380 ns and T1/2\simeq 10 ns. The characteristics of the third one (T
1/2≃ 250 ns) at 5.2 MeV are still questionable but its main decay modes are better known. An extension of the level scheme is
proposed up to 8.4 MeV.Experimental results have been discussed in terms of shell model multiplets and compared with the other
structures observed in N=85 neighbouring nuclei.
Received: 8 November 1999 / Revised version: 13 December 1999 相似文献
19.
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
20.
J. Simpson M.A. Riley R.W. Laird D.J. Hartley F.G. Kondev J. Sweeney A.N. Wilson S.J. Gale M.A. Bentley A.M. Bruce R. Chapman R.M. Clark D.M. Cullen P. Fallon P.D. Forsyth S.J. Freeman P.M. Jones J.C. Lisle A.O. Macchiavelli J.F. Sharpey-Schafer A.G. Smith J.F. Smith D.M. Thompson 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):267-274
A series of new strongly coupled high-K, multi-quasiparticle structures have been observed in the light erbium transitional
nuclei, 159Er and 160Er. The interpretation of these bands is discussed within the framework of the cranked shell model. These sequences, when
taken together with the existing quasiparticle excitations, form a near complete set of low-lying, multi-quasiparticle structures
on which a coherent series of aligned angular momentum, band crossing and blocking arguments can be based. The measured B(M1)/B(E2)
ratios are compared with geometrical calculations to test the proposed configuration assignments.
Received: 19 November 1997 相似文献