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1.
The decay of 215-217Th was investigated by ER-γ-α-γ coincidence measurements. The nuclei were produced by the reaction 170Er(50Ti, xn)220-xTh. Evaporation residues recoiling out of the target were separated in flight by the velocity filter SHIP and stopped in a
position-sensitive 16-strip PIPS-detector in order to study their subsequent decays. Associated γ-rays were detected by a
fourfold Ge-Clover detector. In the present work we extracted new and improved data for 215-217Th including isomeric decays. The results are discussed and compared to previously published data. 相似文献
2.
P. Kuusiniemi F. P. Heßberger D. Ackermann S. Antalic S. Hofmann K. Nishio B. Sulignano I. Kojouharov R. Mann 《The European Physical Journal A - Hadrons and Nuclei》2006,30(3):551-559
The decay of 213, 214Ra was studied by α-γ and γ-γ coincidence measurements. The nuclei were produced in the reactions 170Er(48Ca, xn)218-x
Ra and 170Er(50Ti, 3n)217Th and subsequent α decay of 217Th to 213Ra. Evaporation residues recoiling out of the target were separated in-flight by the velocity filter SHIP and implanted into
a position-sensitive 16-strip PIPS detector in order to study their subsequent decays. Associated γ-rays were detected by
a four-fold Ge-Clover detector. In the present work we extracted new and improved data for 213, 214Ra including isomeric transitions. The results are discussed and compared with previously published data. 相似文献
3.
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
4.
A.N. Andreyev K. Van de Vel A. Barzakh A. De Smet H. De Witte D.V. Fedorov V.N. Fedoseyev S. Franchoo M. Górska M. Huyse Z. Janas U. Köster W. Kurcewicz J. Kurpeta V.I. Mishin K. Partes A. Plochocki P. Van Duppen L. Weissman 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):63-75
Alpha-decay properties of the neutron-deficient isotope 185Pb were studied at the PSB-ISOLDE (CERN) on-line mass separator using the resonance ionisation laser ion source (RILIS). The
nuclei of interest were produced in a 1.4 GeV proton-induced spallation reaction of a uranium graphite target. In contrast
to previous studies, two α-decaying isomeric states were identified in 185Pb. The relative production of the isomers, monitored by their α-counting rates, could be significantly changed when a narrow-bandwidth
laser at the RILIS setup was used to scan through the atomic hyperfine structure. Based on the atomic hyperfine structure
measurements, along with the systematics for heavier odd-mass lead isotopes, the spin and the parity of these states were
interpreted as 3/2- and 13/2+ and their nuclear magnetic moments were deduced. The α-decay energy and half-life value for the I
π = 13/2+ isomer are E
α = 6408(5) keV, T
1/2 = 4.3(2) s, respectively; while for the I
π = 3/2- isomer ( T
1/2 = 6.3(4) s) two α-decays with E
α1 = 6288(5) keV, I
α1 = 56(2)% and E
α2 = 6486(5) keV, I
α2 = 44(2)% were observed. By observing prompt α-γ coincidences new information on the low-lying states in the daughter isotope
181Hg was obtained.
Received: 7 February 2002 / Accepted: 19 February 2002 相似文献
5.
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
6.
G. Giardina G. Fazio G. Mandaglio M. Manganaro C. Saccá N. V. Eremin A. A. Paskhalov D. A. Smirnov S. P. Maydanyuk V. S. Olkhovsky 《The European Physical Journal A - Hadrons and Nuclei》2008,36(1):31-36
We analyze the bremsstrahlung emission obtained by the α -γ coincidence measurements to investigate on the α -decay dynamics
of the 214
Po nucleus. We performed the experiment using a radioactive 226
Ra source leading, by α -decays, to the 214
Po nucleus, and the apparatus with the Si detector for α -particles, the NaI(Tl) detector able to collect photons with energies
up to about 1 MeV. We compare the experimental data with the quantum-mechanical calculations and find a good agreement between
theory and experiment for photon energies up to 765 keV. In the experimental data of the bremsstrahlung spectrum one can see
the presence of slight oscillations. 相似文献
7.
F. P. Heßberger S. Antalic B. Streicher S. Hofmann D. Ackermann B. Kindler I. Kojouharov P. Kuusiniemi M. Leino B. Lommel R. Mann K. Nishio S. Saro B. Sulignano 《The European Physical Journal A - Hadrons and Nuclei》2005,26(2):233-239
The decay of odd-mass mendelevium isotopes ( A = 247-255) has been studied by means of α-γ spectroscopy. Strong evidence for a small α branch in the decay of 253Md was found. γ lines in coincidence with α-decays of 247, 249, 251, 253Md have been observed for the first time. Levels in the einsteinium daughter nuclei were assigned on the basis of α-γ coincidence
measurements. An energy systematics of the 7/2-[514] Nilsson level could be established, showing a correlation with the deformation parameter β2 of the corresponding nuclei. The results are compared with theoretical predictions 相似文献
8.
J. Huikari M. Oinonen A. Algora J. Cederkäll S. Courtin P. Dessagne L. Fraile S. Franchoo H. Fynbo W.X. Huang A. Jokinen A. Knipper F. Marechal C. Miehé E. Nacher K. Peräjärvi E. Poirier L. Weissman J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):359-363
The β-decay of 75Sr to its mirror nucleus 75Rb was studied at the ISOLDE PSB facility at CERN by means of β-delayed γ and proton spectroscopy. The decay Q-value and β-delayed γ intensity were measured for the first time. These results, 10.60±0.22 MeV and 4.5+1.9
-0.7%, together with accurate measurements of the β-decay half-life and β-delayed proton branching ratio yielded the Gamow-Teller
strength 0.35±0.05 for the mirror transition. Implications of the results on studies of deformation effects and on the path
of the rapid proton capture process are discussed.
Received: 26 September 2002 / Accepted: 30 October 2002 / Published online: 18 February 2003
RID="a"
ID="a"e-mail: jussi.huikari@phys.jyu.lfi
Communicated by D. Schwalm 相似文献
9.
F.P. Heßberger S. Hofmann D. Ackermann 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):365-370
Radium isotopes with mass numbers from 209 to 212 have been produced by heavy-ion fusion reactions 204Pb( 12C, xn) 216-Ra. Radioactive decay properties were investigated by means of α- and α-γ-spectroscopy after in-flight separation of the evaporation
residues from the projectile beam by the velocity filter SHIP and implantation into a 16-strip position-sensitive Si detector.
For the even-even nuclei 210,212Ra we identified α transitions into the first-excited 2+-state of the daughter nuclei 206,208Rn. Weak α transitions into excited levels of the odd-A daughter nuclei 205,207Rn were also observed.
Received: 19 August 2002 / Accepted: 6 November 2002 / Published online: 18 February 2003
RID="a"
ID="a"e-mail: f.p.hessberger@gsi.de
Communicated by D. Guerreau 相似文献
10.
A. Gizon J. Genevey C.F. Liang P. Paris D. Barnéoud J. Inchaouh I. Penev A. Plochocki 《The European Physical Journal A - Hadrons and Nuclei》2001,12(3):309-316
An investigation of low-lying energy levels of 130Pr and 130Ce has been made via β-decay. The radioactive parent nuclei were produced via 94,96Mo + 40Ca reactions at 6.8 MeV/nucleon and transported by a He-jet system. Gamma-γ-t, γ-X-t, γ-e--t coincidence measurements were performed. Internal conversion coefficients have been measured with a magnetic spectrometer.
The new β-decay half-life of 130Nd has been determined to be 21(3) s. A partial level scheme of 130Pr at low-spin has been constructed. The β-decay of 130Pr to 130Ce suggests the existence of three β-instable isomeric states in 130Pr, while only one half-life T
1/2 = 40(4) s has been measured. Based on the present work and low-lying excited states in neighbouring odd-mass nuclei, the
spins and parities of isomeric states in 130Pr are proposed to be 2+, (4,5)+ and (7,8±). The ground state in 130Pr is still undetermined.
Received: 20 August 2001 / Accepted: 6 November 2001 相似文献
11.
F. P. Heßberger S. Hofmann D. Ackermann V. Ninov M. Leino S. Saro A. Andreyev A. Lavrentev A. G. Popeko A. V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2000,8(4):521-535
Neutron deficient isotopes of elements Z = 86-92 have been produced by heavy-ion fusion reactions 12C + 208Pb, 209Bi, 22Ne + 208Pb, 51V + 170Er, and 50Ti + 170Er. The evaporation residues were investigated by means of α- and α-γ-spectroscopy after in-flight separation from the projectile
beam by the velocity filter SHIP and implantation into a 16-strip position-sensitive Si-detector. New or improved decay data
for 225, 226U, 216, 217m, 218Pa, 215, 216, 217Th, 214, 215, 216, 216mAc, 214Ra and 213Rn have been obtained.
Received: 5 April 2000 / Accepted: 28 July 2000 相似文献
12.
Yu.N. Novikov H. Schatz P. Dendooven R. Béraud Ch. Miehé A.V. Popov D.M. Seliverstov G.K. Vorobjev P. Baumann M.J.G. Borge G. Canchel Ph. Desagne A. Emsallem W. Huang J. Huikari A. Jokinen A. Knipper V. Kolhinen A. Nieminen M. Oinonen H. Penttilä K. Peräjärvi I. Piqueras S. Rinta-Antila J. Szerypo Y. Wang J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2001,11(3):257-261
A careful investigation of the isomeric transition of the long-lived state at 228.5 keV excitation energy in 80Y has been done. The HIGISOL facility at the Jyv?skyl? isochronous cyclotron has been used. We used the electron magnetic
transporter to prepare an appropriate source and to measure the electron spectra in clean background conditions. The measured
internal conversion coefficient αK = 0.50±0.07 allows unambiguous 1- identification for the 228.5 keV first excited isomeric state in 80Y. With a “bare" half-life of 6.8±0.5 s found in this work, this state is strongly populated in the rp-process during X-ray
bursts and has therefore to be taken into account in X-ray burst model calculations. However, because of the similarity of
the β-decay half-lives of isomeric and ground states, we find a maximum reduction in the effective β-decay lifetime of 80Y of only 17±2%. Our results pave the way for a future investigation of the impact of the isomeric state on the “effective"
80Y proton capture rate.
Received: 14 March 2001 / Accepted: 10 July 2001 相似文献
13.
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
14.
Y. Kojima M. Shibata A. Taniguchi T. Hanafusa E. Yoshida K. Shizuma Y. Kawase S. Yamada 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):331-336
The β--decay of 151Pr produced by the thermal neutron-induced fission of 235U has been studied using an on-line isotope separator. From an internal-conversion electron measurement with a Si(Li) detector,
K-conversion coefficients were obtained for 20 γ-transitions. Spins and parities of 6 excited levels in 151Nd were newly determined from the deduced multipolarities: even parities for the 543 and 627 keV levels, odd parities for
250 and 599 keV, (3/2, 5/2)+ for 685 keV, and (1/2, 3/2)+ for 880 keV. The level structure was compared with the rotation-vibration coupling Nilsson model.
Received: 28 June 2002 / Accepted: 31 October 2002 / Published online: 25 February 2003
RID="a"
ID="a"e-mail: ykojima@hiroshima-u.ac.jp
Communicated by J. ?yst? 相似文献
15.
D. Sohler Zs. Dombrádi J. Blomqvist J. Cederkäll J. Huijnen M. Lipoglavšek M. Palacz A. Atac C. Fahlander H. Grawe A. Johnson A. Kerek W. Klamra J. Kownacki A. Likar L.-O. Norlin J. Nyberg J. Persson D. Seweryniak G. de Angelis P. Bednarczyk D. Foltescu D. Jerrestam S. Juutinen E. Mäkelä M. de Poli H.A. Roth T. Shizuma Ö. Skeppstedt G. Sletten J. Timár S. Törmänen M. Weiszflog 《The European Physical Journal A - Hadrons and Nuclei》2003,16(2):171-175
Excited states of 99Ag were populated via the 50Cr + 58Ni (261 MeV) reaction using the NORDBALL detector array equipped with charged-particle and neutron detector systems for reaction
channel separation. On the basis of the measured γγ-coincidence relations and angular distribution ratios a significantly
extended level scheme has been constructed up to E
x ∼ 7.8 MeV and I = 35/2. The experimental results were described within the framework of the shell model. Candidates for states fully aligned
in the πg
9/2
-3ν(d
5/2, g
7/2)2 valence configuration space were found at 4109 and 6265 keV.
Received: 18 June 2002 / Accepted: 11 October 2002 / Published online: 4 February 2003
RID="a"
ID="a"e-mail: sohler@atomki.hu
Communicated by J. ?yst? 相似文献
16.
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
17.
J.Y. Huh C.S. Lee Y.K. Kwon J.Y. Kim Y. Gono T. Morikawa H. Watanabe M. Shibata S. Motomura T. Tsutsumi T. Fukuchi T. Kishida E. Ideguchi X.H. Zhou A. Odahara S. Kubono J.H. Ha M.K. Cheoun C. Lee J.C. Kim C.-B. Moon S.J. Chae Y.K. Kim J.S. Chai 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):11-14
High-spin states of 155Gd were populated by using the 154Sm(α,3nγ)155Gd reaction at E
α= 33 MeV. γ-γ coincidence, E
γ singles, excitation function, and the DCO ratios were measured. we have identified three intermediate bands with ΔI= 2 feeding the positive yrast band. The bands are interpreted as such candidate bands that are mixed with the negative-parity
ground state band. This observation can provide a plausible explanation for unusually large population of the positive-parity
yrast band observed in a recent Coulomb excitation.
Received: 2 November 1999 相似文献
18.
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
19.
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
20.
Y. Toh S. Yamada A. Taniguchi Y. Kawase 《The European Physical Journal A - Hadrons and Nuclei》1999,4(3):233-238
The structure of 152Nd, produced via β− decay of 152Pr, has been investigated using γ-γ coincidence, γ-γ angular correlation, and β-γ-γ triple coincidence measurements. Praseodymium
activities were obtained by the thermal neutron fission of 235U and collected by the on-line isotope separator KUR-ISOL. Nineteen γ-rays and four excited states were newly found. The spins
of six exited states were determined and the parities of three of them were also deduced. The spin and parity of the 152Pr ground state, which were previously considered as 4−, are proposed to be 4+ by the present study.
Received: 19 October 1998 / Revised version: 22 December 1998 相似文献