共查询到20条相似文献,搜索用时 15 毫秒
1.
E. Kolbe K. Langanke K. Riisager 《The European Physical Journal A - Hadrons and Nuclei》2001,11(1):39-45
Future facilities will allow the exploration of extremely neutron-rich nuclei far from the valley of stability. It is discussed
that the strong-neutron excess results in changes in the collective excitations of such nuclei compared to conventional stable
nuclei. We propose muon capture as an experimental tool to explore such changes. We will quantify our discussion by the calculation
of the total and differential muon capture rates on selected calcium isotopes between 40Ca and 60Ca. Our calculations are based on the random phase approximation and agree nicely with the measured rates for 40Ca and 44Ca.
Received: 6 April 2001 / Accepted: 14 May 2001 相似文献
2.
S.-W. Xu Y.-X. Xie X.-D. Wang Z.-K. Li B. Guo C.-G. Leng C.-F. Wang Y. Yu 《The European Physical Journal A - Hadrons and Nuclei》2001,11(3):277-278
The very neutron-deficient isotope 133Sm was produced by irradiation of an enriched target of 96Ru with 40Ca and studied by using a helium-jet fast tape transport system in combination with X-γ and γ-γ coincidence measurements.
A simple ( EC + β+) decay scheme of 133Sm was proposed for the first time. As a by-product 133Pr was produced simultaneously because of the 98-102Ru content of the ruthenium target. The half-life of a 11/2- low-lying isomeric state in 133Pr was measured to be 1.1±0.2 s.
Received: 22 March 2001 / Accepted: 18 July 2001 相似文献
3.
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
4.
B. Kamys P. Kulessa H. Ohm K. Pysz Z. Rudy H. Ströher W. Cassing 《The European Physical Journal A - Hadrons and Nuclei》2001,11(1):1-4
The β-delayed proton precursor 149Yb was synthesized in the reaction 112Sn(40Ca, 3n) and identified by using a proton-gamma coincidence measurements in combination with a helium-jet fast tape transport
system. Its β-delayed proton spectrum was observed. The half-life of 149Yb was determined to be 0.7±0.2 s. The 253, 101, and 365 keV γ transitions in 147Dy, following β-delayed proton emission of 148Ho decay, were reported for the first time.
Received: 14 March 2001 / Accepted: 26 September 2001 相似文献
5.
O. Sorlin C. Donzaud F. Nowacki J.C. Angélique F. Azaiez C. Bourgeois V. Chiste Z. Dlouhy S. Grévy D. Guillemaud-Mueller F. Ibrahim K.-L Kratz M. Lewitowicz S.M. Lukyanov J. Mrasek Yu.-E. Penionzhkevich F. de Oliveira Santos B. Pfeiffer F. Pougheon A. Poves M.G. Saint-Laurent M. Stanoiu 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):55-61
The neutron-rich nuclei 23
60-63V have been produced at GANIL via interactions of a 61.8A·MeV 76Ge beam with a 58Ni target. Beta-decay to 24
60-63Cr has been investigated using combined β- and γ-ray spectroscopy. Half-lives of the 60-63V nuclei have been determined, and the existence of a beta-decay isomer in the 60V nucleus is strongly supported. The observation of low-energy 2+ states in 60Cr (646keV) and 62Cr (446keV) suggests that these isotopes are strongly deformed with β2 ∼ 0.3. This is confirmed by shell model calculations which show the dominant influence of the intruder g and d orbitals to obtain low 2+ energies in the neutron-rich Cr isotopes.
Received: 13 June 2002 / Accepted: 27 August 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: sorlin@ipno.in2p3.fr
Communicated by D. Guerreau 相似文献
6.
D. Guillemaud-Mueller 《The European Physical Journal A - Hadrons and Nuclei》2002,13(1-2):63-67
The structure of neutron-rich light nuclei around N = 20, 28 has been investigated at GANIL by means of in-beam gamma spectroscopy using fragmentation reactions of 36S and 48Ca beams on a Be target. Gamma decay of relatively high-lying excited states have been measured for the first time in nuclei
around 32Mg and 44S. Level schemes are proposed and discussed for a large number of these neutron-rich nuclei around N = 20 and N = 28.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
7.
L. Zhang K. Morita Q.Y. Hu A. Yoshida J.H. Zhao Z.K. Li J.W. Zheng Y.H. Pu H. Kudo H. Wei C.F. Wang H.M. Fan J.N. Gu Y. Yano 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):299-301
A new determination for the levels of the nucleus 208Tl was performed by measuring the γ-rays following the β--decay of 208Hg. Twenty-six γ-rays were assigned and three new levels of 208Tl at 1.728 MeV, 1.652 MeV and 1.362 MeV have been affirmed. A partial 208Hg decaying γ scheme was proposed. The experimental level structure was compared with a shell model calculation.
Received: 12 August 2002 / Accepted: 19 December 2002 / Published online: 25 February 2003
RID="a"
ID="a"e-mail: Li41zhang@yahoo.com
Communicated by W. Henning 相似文献
8.
A. Korgul H. Mach B. Fogelberg W. Urban W. Kurcewicz T. Rzaca-Urban P. Hoff H. Gausemel J. Galy J.L. Durell W.R. Phillips A.G. Smith B.J. Varley N. Schulz I. Ahmad L.R. Morss M. Górska V.I. Isakov K.I. Erokhina J. Blomqvist F. Andreozzi F. Coraggio A. Covello A. Gargano 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):181-184
Excited states in the 134Sb nucleus, populated in the β--decay of 134Sn, have been studied at the mass separator OSIRIS. The 134Sn activity was produced via fast neutron-induced fission of 238U target. A main result was the discovery of a very low-lying first-excited state of 134Sb, at 13keV, which has led to a strong revision of the level scheme. The new results are compared with different theoretical
calculations and with the known data for the analogous neutron and proton two-particle nucleus in the 208Pb region. On the basis of this comparison, the energy of the ( πg
7/2νf
7/2)7- isomer is estimated to be about 250keV, some 100keV lower than previously reported.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: anovak@fuw.edu.pl 相似文献
9.
A.L. Barabanov 《The European Physical Journal A - Hadrons and Nuclei》1999,6(4):373-374
It is shown that new spin-orbit-like terms appear in the effective nonrelativistic weak Hamiltonian for nucleon provided
that nuclear potential is taken into account. Arguments for their considerable enhancement, in particular, in relativistic
nuclear model of Walecka are advanced.
Received: 29 July 1999 相似文献
10.
M. Asai K. Tsukada S. Ichikawa M. Sakama H. Haba Y. Nagame I. Nishinaka K. Akiyama A. Toyoshima T. Kaneko Y. Oura Y. Kojima M. Shibata 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):17-19
A new neutron-deficient berkelium isotope 241Bk produced in the 239Pu(6Li, 4n) reaction has been identified using a gas-jet coupled on-line isotope separator. Cm K and L X-rays associated with the EC decay of 241Bk were observed in the mass-241 fraction, and three γ transitions were attributed to the EC decay of 241Bk through X-γ coincidences. The half-life of 241Bk was determined to be 4.6±0.4 min which is 1/2-1/4 of that of theoretical predictions. The half-life value and the observed
γ transitions can be consistently explained as a consequence of the allowed EC transition of π7/2+[633] → ν7/2+[624].
Received: 14 October 2002 / Accepted: 6 November 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: asai@tandem.tokai.jaeri.go.jp
Communicated by J. ?yst? 相似文献
11.
N.A. Orr 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):109-113
Clustering is a relatively widespread phenomenom which takes on many guises across the nuclear landscape. Selected topics
concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative
examples taken from the Be isotopic chain. The production and detection of multineutron clusters is also briefly presented.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: orr@caelav.in2p3.fr 相似文献
12.
K. Schmidt C. Mazzocchi R. Borcea J. Döring S. Galanopoulos M. Górska H. Grawe S. Harissopulos M. Hellström Z. Janas R. Kirchner G. Kriembardis M. La Commara A. N. Ostrowski G. Rainovski E. Roeckl 《The European Physical Journal A - Hadrons and Nuclei》2000,8(3):303-306
The very neutron-deficient isotope 93Pd was produced in fusion-evaporation reactions of a 40Ca beam on a 58Ni target. The reaction products were separated at the GSI Online Mass Separator, using ion sources of the FEBIAD type. The
-decay properties of 93Pd were studied by detecting -delayed protons and -delayed -rays. The feeding of excited levels in the daughter nucleus 93Rh and the -decay half-life of 93Pd were determined. The experimental results are discussed in comparison to shell model predictions.
Received: 19 April 2000 / Accepted: 17 June 2000 相似文献
13.
R. Broda 《The European Physical Journal A - Hadrons and Nuclei》2002,13(1-2):1-4
The use of deep-inelastic heavy-ion reactions for the spectroscopy of neutron-rich nuclei is discussed. Conclusions from the
N/Z equilibration process studies are outlined and examples of spectroscopic results obtained for the neutron-rich spdf shell nuclei, N = 82 isotones and nuclei from the 208Pb region are reviewed.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
14.
S.-W. Xu Y.-X. Xie Z.-K. Li X.-D. Wang B. Guo C.-G. Leng C.-F. Wang Y. Yu 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):347-351
The 1/2+ ground state and a 11/2- isomer of very neutron-deficient isotope 143Dy were produced by irradiation of an enriched target of 106Cd with 40Ca and studied by using a helium-jet fast tape-transport system in combination with proton-γ, X-γ and γ-γ coincidence measurements.
A simple ( EC + β+) decay scheme of 143mDy with a half-life of 3.0(3) s and a tentative ( EC + β+) decay scheme of 143gDy with a half-life of 5.6(10) s are proposed. As a by-product, the 347- and 545-keV γ transitions in 138Sm following the β-delayed proton emission of 139Gd decay and the 323-keV γ transition in 139Eu following the β-delayed proton emission of 140Tb decay could be observed for the first time.
Received: 20 August 2002 / Accepted: 28 October 2002 / Published online: 11 February 2003
RID="a"
ID="a"e-mail: xsw@ns.lzb.ac.cn
Communicated by D. Schwalm 相似文献
15.
E. Roeckl 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):139-144
This review focusses on recent results obtained by using fusion-evaporation reactions for the production of N ≃ Z nuclei, the on-line mass separator of GSI for the preparation of the radioactive samples, and charged-particle and γ-ray
detectors for performing decay spectroscopy. The experimental results on prompt and β-delayed disintegration modes are discussed
in comparison with theoretical model predictions.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: e.roeckl@gsi.de 相似文献
16.
S.-W. Xu Z.-K. Li Y.-X. Xie X.-D. Wang B. Guo C.-G. Leng Y. Yu 《The European Physical Journal A - Hadrons and Nuclei》2001,11(4):375-377
β-delayed proton precursors 93Pd and 92Rh were produced by the irradiation of 58Ni with a 40Ca beam, and identified using proton-gamma coincidence measurements in combination with a helium-jet fast tape transport system.
The half-lives of 93Pd and 92Rh were determined to be 1.3(2), 3.0(8) s, respectively. The measured energy spectrum of β-delayed protons and the estimated
relative branching ratios to the final states in the daughter nuclei were fitted by a statistic model calculation, and then
the ground-state spin and parity of 93Pd were assigned as 9/2±.
Received: 13 April 2001 / Accepted: 22 August 2001 相似文献
17.
G. Canchel L. Achouri J. Äystö R. Béraud B. Blank E. Chabanat S. Czajkowski P. Dendooven A. Emsallem J. Giovinazzo J. Honkanen A. Jokinen M. Lewitowicz C. Longour F. de Oliviera Santos K. Peräjärvi M. Staniou J.C. Thomas 《The European Physical Journal A - Hadrons and Nuclei》2001,12(4):377-380
In an experiment performed at the GANIL LISE3 facility, radioactive 27S isotopes have been produced by projectile fragmentation of a 95 AMeV 36Ar primary beam. After selection by means of the LISE3 separator, the isotope of interest was implanted in a silicon-detector
telescope where its half-life ( T
1/2 = 15.5(15) ms) and its main decay branches were measured.
Received: 19 October 2001 / Accepted: 5 December 2001 相似文献
18.
M.?Madurga M. J.G.?Borge H. O.U.?Fynbo B.?Jonson G.?Nyman Y.?Prezado K.?Riisager O.?Tengblad IS-?collaboration TONERRE?collaboration 《The European physical journal. Special topics》2007,150(1):137-138
The aim of this work is to find out the origin of the anomalous
resonance in 8Be seen in the reactions through excited states in 9Be.
We have populated the 9Be excited states by β-decay of 9Li.
Energy and direction of the two α particles has been detected and the
neutron spectra reconstructed. In our work we identified the “anomalous resonance" in
8Be observed in several reaction studies
as coming from the decay of the 2.43 and 2.78 MeV states in 9Be.
This anomalous resonance appears when
the two detected α particles are assumed to form a resonance in 8Be.
We argued that the main decaying channels for these two levels in 9Be do not involve
8Be. 相似文献
19.
C. Mazzocchi Z. Janas J. Döring M. Axiotis L. Batist R. Borcea D. Cano-Ott E. Caurier G. de Angelis E. Farnea A. Faßbender A. Gadea H. Grawe A. Jungclaus M. Kapica R. Kirchner J. Kurcewicz S.M. Lenzi T. Martínez I. Mukha E. Nácher D.R. Napoli E. Roeckl B. Rubio R. Schwengner J.L. Tain C.A. Ur 《The European Physical Journal A - Hadrons and Nuclei》2001,12(3):269-277
By using the fusion-evaporation reaction 28Si(36Ar,p3n) and spectroscopy of β-delayed γ-rays and charged particles on mass-separated sources, β-decay properties of the neutron-deficient
isotope 60Ga were studied for the first time. The half-life of 60Ga was determined to be 70(15) ms, and, based on βγγ coincidences, the isobaric-analogue state in 60Zn was identified at 4851.9(7) keV. A semiempirical proton separation energy value of 40(70) keV was deduced for 60Ga. The experimental results on half-life, mass excess, proton separation energy, and structure of the 60Zn daughter states are discussed in comparison with various model predictions, including large-scale shell model calculations.
Received: 4 September 2001 / Accepted: 12 November 2001 相似文献
20.
Strengths of Gamow-Teller decays of Tz = ±1 nuclei to Tz = 0 odd-odd nuclei have been calculated by using spherical shell model and deformed Nilsson wave functions. The role and
competition of the microscopic direct and spin-flip mechanisms generating Gamow-Teller transitions are analyzed. Analytical
expressions derived for the B(GT) values give useful insight into the regularities of B(GT) values along the N = Z line. The crucial role of configuration mixing is discussed. 相似文献