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1.
Li Zhankui Xu Shuwei Xie Yuanxiang Zhang Tianmei Ma Ruichang Du Jinzhou Guo Yingxiang Ge Yuanxiu Wang Chunfang Guo Bing Xing Jianping 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):1-5
The (EC+β+) decay of 128Ce was reinvestigated in the 116Sn (16O, 4n) reaction by using a helium-jet tape transport system. The close half-lives of 128Ce and 129Ce made it difficult to separate the decay γ rays of both nuclei apart. Instead of the excitation-function measurements, both
reactions of 16O+116Sn and 16O+117Sn were carried out, and from their comparisons, the decay γ rays of 128Ce were clearly told from those of 129Ce. Based on X-γ and γ-γ coincidence measurements, a detailed (EC +β+) decay scheme of 128Ce has been proposed, which revises the previous one.
Received: 29 September 1999 / Revised version: 5 November 1999 相似文献
2.
D.C. Biswas R.K. Choudhury M. Cinausero B. Fornal D.V. Shetty G. Viesti D. Fabris E. Fioretto M. Lunardon G. Nebbia G. Prete D. Bazzacco M. DePoli D.R. Napoli C.A. Ur G. Vedovato 《The European Physical Journal A - Hadrons and Nuclei》2000,7(2):189-195
Measurements of fission fragment yields and neutron multiplicities have been carried out for the Mo-Ba fragment pairs in
the spontaneous fission of 252Cf, using the γ-ray spectroscopy technique to analyze γ-γ-γ coincidence data. Prompt γ -ray multiplicities were also measured
as a function of the number of neutrons emitted in the fission process leading to the Mo-Ba partition. We do not observe the
enhancement in the yields of events with high neutron emission multiplicity (νn > 7) that has been associated to a second fission mode leading to the production of hyperdeformed Ba fragments, as reported
in some earlier studies. The average γ-ray multiplicity is found to be rather weakly dependent on the number of neutrons emitted
in the fission process.
Received: 21 July 1999 / Revised version: 19 November 1999 相似文献
3.
N. Gelli F. Lucarelli M. Cinausero E. Fioretto G. Prete D. Fabris M. Lunardon G. Nebbia G. Viesti D. Bazzacco C.A. Ur D.R. Napoli P. Pavan C. Rossi Alvarez P.F. Bortignon E.M. Fiore L. Fiore V. Paticchio B. Fornal 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):361-365
The high energy γ-rays from the fusion-evaporation reaction 101 MeV 19F +181Ta have been measured in coincidence with different γ-ray fold windows or discrete γ-rays in final residual nuclei. The line-shape
analysis of the high energy γ-ray spectra confirms the large deformation of the 200Pb nuclei at high angular momenta. Coincidences with discrete γ-transitions evidence a strong correlation between γ-rays in
the Giant Dipole Resonance region (Eγ≥ 8 MeV) and final evaporation residues.
Received: 14 September 1999 / Revised version: 17 December 1999 相似文献
4.
H. Tiesler H. Klein A. Fitzler I. Wiedenhöver P. von Brentano 《The European Physical Journal A - Hadrons and Nuclei》2000,9(2):157-160
High-spin states in 143Pm have been investigated via the 128Te(19F,4nγ)143Pm reaction using techniques of in-beam γ-spectroscopy. γ-ray singles, γ-γ coincidences, γ-ray anisotropies and DCO ratios
have been measured. Based on these measurements, the level scheme of 143Pm has been extended up to an excitation energy of 10535.4 keV, including 48 new γ-rays deexciting 28 new levels. The yrast
levels in 143Pm can be understood qualitatively in the framework of a weak-coupling model.
Received: 10 July 2000 / Accepted: 12 October 2000 相似文献
5.
J. Kurpeta A. Andreyev J. Äystö A.-H. Evensen M. Huhta M. Huyse A. Jokinen M. Karny E. Kugler J. Lettry A. Nieminen A. Płochocki M. Ramdhane H.L. Ravn K. Rykaczewski J. Szerypo P. Van Duppen G. Walter A. Wöhr 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):49-54
The decay of the neutron–rich isotope 216Bi, produced by proton–induced spallation at the PS Booster–ISOLDE facility, was investigated by β-γγ, αγ coincidence and
spectrum-multiscaling measurements. A new method for reducing isobaric contamination enabled to cover the unknown region “east”
of 208Pb for the isobaric chain A=216. The half-life of the β decay of 216Bi was found as T1/2= 135 ± 5 s. Its decay scheme was extended and the possible shell model configurations are proposed.
Received: 13 July 1999 / Revised version: 22 September 1999 相似文献
6.
J. Kurpeta G. Lhersonneau J.C. Wang P. Dendooven A. Honkanen M. Huhta M. Oinonen H. Penttilä K. Peräjärvi J.R. Persson A. Płochocki J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,2(3):241-243
Very neutron–rich fission products of the mass chain A=113 obtained from the IGISOL on–line mass separator have been investigated
by γγ coincidence techniques and γ-spectra multiscaling. Gamma–rays following β–decay of 113Tc have been observed for the first time and a new 0.5 s isomeric state has been found in 113Ru.
Received: 10 February 1998 相似文献
7.
R. Loritz O. Iordanov E. Galindo A. Jungclaus D. Kast K.P. Lieb C. Teich F. Cristancho Ch. Ender T. Härtlein F. Köck D. Schwalm 《The European Physical Journal A - Hadrons and Nuclei》1999,6(3):257-268
Subpicosecond lifetimes of high spin states in the rotational nuclei 73Se, 74Se and 74Br have been measured using the 58Ni +19F compound reaction and the Doppler Shift Attenuation method. Six EUROBALL Cluster detectors arranged in cube geometry allowed
us to select the relevant transitions in γγ coincidence mode. The high counting statistics achieved in this setup also facilitated
the determination of average sidefeeding times, which were found to agree rather well with the results of Monte-Carlo calculations
of the particle and γ-ray evaporation process. The deduced quadrupole strengths and deformations are compared with the results
of previous measurements and the predictions of Cranked Shell Model calculations. In 74Br, a large and constant prolate deformation of β2= 0.37(1) was found for the presumed 4+ and 3− two-quasiparticle bands.
Received: 2 July 1999 相似文献
8.
B. Aengenvoort W. Korten H. Hübel S. Chmel A. Görgen U.J. van Severen W. Pohler R. Zinken T. Härtlein C. Ender F. Köck P. Reiter D. Schwalm F. Schindler J. Gerl R. Schubart F. Azaiez S. Bouneau J. Duprat I. Deloncle 《The European Physical Journal A - Hadrons and Nuclei》1998,1(4):359-364
Three mini-orange conversion–electron spectrometers and four Euroball Ge Cluster detectors have been used for γ–e- coincidence spectroscopy of superdeformed 135Nd. Transitions within the superdeformed band are shown to have the expected E2 multipolarity. The 766.5–keV transition which
links the band to a positive-parity state has a conversion coefficient consistent with M1 multipolarity. Consequently, positive
parity is deduced for the superdeformed band. No evidence for E0 transitions was found.
Received: 22 December 1997 / Revised version: 19 January 1998 相似文献
9.
A.P. Byrne A.M. Baxter G.D. Dracoulis S.M. Mullins T. Kibédi T.R. McGoram K. Helariutta J.F.C. Cocks P. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen P. Kuusiniemi M. Leino M. Muikku P. Nieminen P. Rahkila A. Savelius 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):41-44
Lifetime measurements of states in nuclei with A=187 and 188 have been performed, using reactions between 155Gd and 36Ar and following the transport of evaporation residues to the focal plane of a gas-filled recoil separator. In a separate
experiment using the 159Tb(32S, 4n) reaction the γ-decay of isomeric levels in 187Tl has been studied using delayed γ-γ coincidence measurements. From observation of their subsequent γ decay, the mean lifetimes
were measured to be 1000 ± 55 ns and 1600 ± 100 ns. Although it was not possible to characterize the isomers completely, they
are proposed as candidates for one-proton, two-neutron excitations. In the course of this study, the decay of an isomer in
188Pb was also observed and its lifetime was measured as 1150 ± 30 ns, and limits of 20–600 ns were placed on the meanlife of
an isomer conjectured in 187Pb.
Received: 20 August 1999 相似文献
10.
D.C. Biswas B.K. Nayak M. Cinausero B. Fornal G. Viesti D. Bazzacco M. DePoli D. Fabris E. Fioretto M. Lunardon D.R. Napoli G. Nebbia G. Prete C.A. Ur G. Vedovato 《The European Physical Journal A - Hadrons and Nuclei》1999,4(4):343-348
The high energy γ-ray emission accompanying the spontaneous fission of 252Cf has been measured in coincidence with individual fission fragments selected by discrete γ-ray transitions. The enhancement
of the γ-ray emission probability in the energy range Eγ= 3–8 MeV has been observed for the fission fragments in the region of nearly symmetric mass splitting, confirming results
reported in previous investigations. The γ-γ coincidence technique employed in the present work clearly demonstrate that the
major contribution to this enhancement is caused by the fission channels where one fragment is near to the N= 82 or Z= 50 shell closures. The high energy γ-ray emission probability does not show any significant dependence on the number of
neutrons emitted in the fission process, supporting the hypothesis that high energy γ-rays are mainly emitted from the fragments
after the neutron evaporation.
Received: 22 December 1998 相似文献
11.
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
12.
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
13.
Y. Toh S. Yamada A. Taniguchi Y. Kawase 《The European Physical Journal A - Hadrons and Nuclei》1998,2(4):331-332
Abstact: Multipolarities of γ-rays in 152Nd have been studied by conversion electron measurements in the β− decay of 152Pr. The praseodymium activities were obtained by the thermal neutron fission of 235U and followed with the on-line isotope separator KUR–ISOL. Conversion electrons and γ-rays were measured with a Si(Li) detector
and a HPGe detector, respectively. The two γ-rays, 226 keV and 285 keV, were decided to have the multipolarities of the E1
transition. The spins and parities of the 1600 keV and 1542 keV levels were determined to be 3+ and 2+, respectively.
Received: 14 April 1998 相似文献
14.
J. Mrázek M. Honusek A. Špalek J. Bielčík J. Slívová J. Adam A.A. Pasternak 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):399-408
The results of in-beam investigations of excited states of 99Ru using the 98Mo(α,3n) reaction are presented. Angular distributions of γ–rays and γ–γ coincidences have been measured. Excited states have
been identified up to an energy of E = 5603 keV and spin of Iπ= 31/2−. Mean lifetimes τ have been determined using the DSA method for eleven levels. Aligned angular momenta are discussed and
the probable (νh
11/2) origin of a backbending at frequency about 0.5 MeV was confirmed. The possible role of (νd
5/2) alignment at frequencies above 0.5 MeV was pointed out.
Received: 13 January 1999 / Revised version: 26 March 1999 相似文献
15.
Th. Andersson D. Rudolph C. Baktash J. Eberth C. Fahlander D. Haslip D.R. LaFosse S.D. Paul D.G. Sarantites C.E. Svensson H.G. Thomas J.C. Waddington W. Weintraub J.N. Wilson B.A. Brown 《The European Physical Journal A - Hadrons and Nuclei》1999,6(1):5-8
High-spin states of the mass A= 39 mirror pair 39K and 39Ca were investigated via the fusion-evaporation reaction 28Si +16O at 125 MeV beam energy. The Gammasphere array in conjunction with the 4π charged-particle detector array Microball and neutron detectors was used to detect γ rays in coincidence with evaporated light particles. The results of the first
high-spin study of the T
z=−1/2 nucleus 39Ca are discussed in terms of mirror symmetry and compared to spherical shell-model calculations in the 1d
3/2–; 1f
7/2 configuration space.
Received: 18 August 1999 相似文献
16.
B. Cederwall T. Bäck R. Wyss A. Johnson J. Cederkäll M. Devlin J. Elson D.R. LaFosse F. Lerma D.G. Sarantites R.M. Clark P. Fallon I.Y. Lee A.O. Macchiavelli R.W. Macleod 《The European Physical Journal A - Hadrons and Nuclei》1999,5(3):251-255
A superdeformed band consisting of a cascade of ten γ-ray transitions has been identified and assigned to the nucleus 89Tc, close to the proton dripline. The quadrupole moment of the band (Q
t= 6.7+3.0
−2.3
eb, as measured by the Residual Doppler Shift Method) as well as a large dynamic moment of inertia point to a highly elongated
shape. With a relative population of approximately 15% of the γ-ray flux in the 89Tc exit channel, the band is among the most intense superdeformed bands observed to date.
Received: 6 July 1999 相似文献
17.
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
18.
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
19.
Y.H. Zhang S.Q. Zhang Q.Z. Zhao S.F. Zhu H.S. Xu X.H. Zhou Y.X. Guo X.G. Lei J. Lu Q.B. Gou H.J. Jin Z. Liu Y.X. Luo X.F. Sun Y.T. Zhu X.G. Wu S.X. Wen C.X. Yang 《The European Physical Journal A - Hadrons and Nuclei》1998,1(2):119-121
High spin states in 170Ta have been studied via 159Tb(16O,5nγ)170Ta reaction through excitation functions, K X-γ and γ-γ-t coincidence measurements. Three rotational bands have been identified
among which one coupled band and an unfavored δI=2 E2 transition sequence are newly found in this work. The possible quasiparticle
configurations of these bands are discussed.
Received: 7 November 1997 相似文献
20.
D. Rudolph C. Baktash M.J. Brinkman M. Devlin H.-Q. Jin D.R. LaFosse L.L. Riedinger D.G. Sarantites C.-H. Yu 《The European Physical Journal A - Hadrons and Nuclei》1999,4(2):115-145
High-spin states of nuclei near doubly magic 56Ni were studied with the reaction 28Si(36Ar,xpynzα) at 136 MeV beam energy. The Gammasphere array in conjunction with the 4π charged-particle detector array Microball and
neutron detectors were used to detect γ rays in coincidence with evaporated light particles. The resulting extensive decay
schemes of 54Fe, 54,55Co, 56,57Ni, and 58Cu are compared to shell model calculations in the fp shell.
Received: 19 September 1998 / Revised version: 27 November 1998 相似文献