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1.
A. Bouzed S. Kröger D. Zimmermann H.-D. Kronfeldt G. Guthöhrlein 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):57-62
We report on hyperfine structure measurements in 21 lines of atomic niobium in the spectral region from 640 nm to 870 nm by
means of optogalvanic laser spectroscopy and laser induced fluorescence spectroscopy using a hollow cathode discharge and
a tunable single-mode cw ring laser. Hyperfine structure constants A and B of altogether 29 excited energy levels were determined, 18 of them for the first time.
Received 18 July 2002 / Received in final form 8 November 2002 Published online 4 February 2003
RID="a"
ID="a"e-mail: sk@kalium.physik.tu-berlin.de 相似文献
2.
E. J. van Duijn S. Witte R. Zinkstok W. Hogervorst 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(1):25-29
The 4
d
10
1
S0 ground-state transitions to the 4
d
9
5
p configuration of palladium (Pd) have been studied. For this purpose, a tunable, single-mode, deep-UV cw laser has been built
to generate the sum frequency of a frequency-doubled Ti:S laser with a second Ti:S laser. The produced wavelengths range from
244 to 276 nm. From the measured spectra the frequency splitting due to hyperfine structure and isotope shift, the hyperfine structure
A and B constants and the lifetimes of the states have been extracted.
Received 3 October 2001 相似文献
3.
P. Bringel H. Hübel H. Amro M. Axiotis D. Bazzacco S. Bhattacharya R. Bhowmik J. Domscheit G.B. Hagemann D.R. Jensen Th. Kröll S. Lunardi D.R. Napoli A. Neußer S.C. Pancholi C.M. Petrache G. Schönwaßer A.K. Singh C. Ur 《The European Physical Journal A - Hadrons and Nuclei》2003,16(2):155-158
High-spin states in 161Lu and 162Lu have been investigated using the GASP γ-ray spectrometer array. Excited states in these nuclei have been populated through
the 100Mo(65Cu, xn) reaction at a beam energy of 260 MeV. Four presumably triaxial superdeformed bands, three in 162Lu and one in 161Lu, have been observed. This is the first evidence for triaxial superdeformation in the two isotopes.
Received: 18 October 2002 / Accepted: 21 November 2002 / Published online: 4 February 2003
RID="a"
ID="a"e-mail: bringel@iskp.uni-bonn.de
RID="b"
ID="b"Present address: Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520, USA.
RID="c"
ID="c"Present address: Physik Department, Technische Universit?t München, James Franck Str., D-85748 Garching, Germany.
Communicated by D. Schwalm 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.
G. Schönwaßer H. Hübel G.B. Hagemann J. Domscheit A. Görgen B. Herskind G. Sletten J.N. Wilson D.R. Napoli C. Rossi-Alvarez D. Bazzacco R. Bengtsson H. Ryde P.O. Tjøm S.W. Ødegård 《The European Physical Journal A - Hadrons and Nuclei》2002,13(3):291-296
Lifetimes of states in the yrast superdeformed bands of 163Lu and 164Lu were determined in a Doppler-shift attenuation-method experiment. From fractional Doppler shifts and line shapes, average
transition quadrupole moments, Q
t = 8.2-0.6
+1.0 b and 7.1-0.6
+0.5 b, were deduced for one of the bands in 163Lu and 164Lu, respectively. These values are much larger than the quadrupole moment of the normal-deformed yrast band in 163Yb, Q
t = 4.9-0.4
+1.3 b, that was also determined in this experiment. Comparison to cranking calculations indicates that both superdeformed bands
correspond to a local potential energy minimum with a pronounced triaxiality, γ∼ 20°.
Received: 8 November 2001 / Accepted: 9 January 2002 相似文献
6.
7.
F. Le Blanc L. Cabaret J.E. Crawford S. Essabaa V. Fedoseyev W. Geithner J. Genevey M. Girod R. Horn G. Huber S. Kappertz J. Lassen J.K.P. Lee G. Le Scornet V. Mishin R. Neugart J. Obert J. Oms A. Ouchrif S. Peru J. Pinard H. Ravn B. Roussière J. Sauvage D. Verney 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):49-51
Laser spectroscopy measurements have been carried out on the very neutron-rich tin isotopes with the COMPLIS experimental
setup. Using the 5s
25p
23
P
0 → 5s
25p6s
3
P
1 optical transition, hyperfine spectra of 126-132Sn and 125m, 127m, 129m-131mSn where recorded for the first time. The variation of the mean-square charge radius ( δ〈r
2〉) between these nuclei and nuclear moments of the isomers and the odd isotopes were thus measured. An odd-even staggering
which inverts at A = 130 is clearly observed. This indicates a small appearance of a plateau on the δ〈r
2〉 which has to be confirmed by measuring the isotope shift beyond A = 132.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: leblanc@ipno.in2p3.fr 相似文献
8.
9.
T. Mazet J. Tobola B. Malaman 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,33(2):183-191
The electronic structure of the RFe
6
Ge
6
compounds ( R
=
Sc, Lu, Ti, Zr, Hf and Nb) of HfFe
6
Ge
6
-type structure has been studied using the muffin-tin Korringa-Kohn-Rostoker method in a non-relativistic approach. The chemical
bonding is analyzed based on the l-decomposed site projected densities of states. Spin-dependent changes in the R nd- Fe 3d covalent bond are shown to be responsible for the experimentally observed rise in the Fe moment and hyperfine field upon
increasing the R valency. The limited quantitative agreement between theoretical and experimental values is interpreted as
being due to a non-negligible orbital moment and to a significant asphericity in the spin density at the iron site. The theoretical
results also forecast a strong increase of the Ge(2e) transferred hyperfine field with the R valency.
Received 20 December 2002 Published online 4 June 2003
RID="a"
ID="a"e-mail: Thomas.Mazet@lcsm.uhp-nancy.fr
RID="b"
ID="b"Associé au CNRS (UMR 7555) 相似文献
10.
P. Egelhof G.D. Alkhazov M.N. Andronenko A. Bauchet A.V. Dobrovolsky S. Fritz G.E. Gavrilov H. Geissel C. Gross A.V. Khanzadeev G.A. Korolev G. Kraus A.A. Lobodenko G. Münzenberg M. Mutterer S.R. Neumaier T. Schäfer C. Scheidenberger D.M. Seliverstov N.A. Timofeev A.A. Vorobyov V.I. Yatsoura 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):27-33
Proton-nucleus elastic scattering at intermediate energies, a well-established method for probing nuclear-matter density distributions
of stable nuclei, was applied for the first time to exotic nuclei. This method is demonstrated to be an effective means for
obtaining accurate and detailed information on the size and radial shape of halo nuclei. Absolute differential cross-sections
for small-angle scattering were measured at energies near 700 MeV/u for the neutron-rich helium isotopes 6He and 8He, and more recently for the lithium isotopes 6Li, 8Li, 9Li and 11Li, using He and Li beams provided by the fragment separator FRS at GSI Darmstadt. Experiments were performed in inverse kinematics
using the hydrogen-filled ionization chamber IKAR which served simultaneously as target and recoil-proton detector. For deducing
nuclear-matter distributions, differential cross-sections calculated with the aid of the Glauber multiple-scattering theory,
using various parametrizations for the nucleon density distributions as input, were fitted to the experimental cross-sections.
The results on nuclear-matter radii and matter distributions are presented, and the significance of the data for a halo structure
is discussed. Nuclear-matter distributions obtained for 6He and 8He conform with the concept that both nuclei compose of α-particle like cores and significant neutron halos. The matter distribution
in 11Li exhibits, as expected from previous reaction cross-section studies with nuclear targets, the by far most extended halo
component of all nuclei being investigated. In addition the present data allow a quantitative comparison of the structure
of the He and Li isobares of either the mass number A = 6 or A = 8. The measured differential cross-sections have also been used for probing density distributions as predicted from various
microscopic calculations. A few examples are presented.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: p.egelhof@gsi.de 相似文献
11.
F. Azaiez M. Belleguic D. Sohler M. Stanoiu Zs. Dombrádi O. Sorlin J. Timár F. Amorini D. Baiborodin A. Bauchet F. Becker C. Borcea C. Bourgeois Z. Dlouhy C. Donzaud J. Duprat D. Guillemaud-Mueller F. Ibrahim M.J. Lopez R. Lucas S.M. Lukyanov V. Maslov J. Mrazek C. Moore F. Nowacki B.M. Nyakó Yu.-E. Penionzhkevich M.G. Saint-Laurent F. Sarazin J.A. Scarpaci G. Sletten C. Stodel M. Taylor C. Theisen G. Voltolini 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):93-97
The structure of neutron-rich light nuclei around N = 20 and 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: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: azaiez@ipno.in2p3.fr 相似文献
12.
13.
I. Dillmann M. Hannawald U. Köster V.N. Fedoseyev A. Wöhr B. Pfeiffer D. Fedorov J. Shergur L. Weissman W.B. Walters K.-L. Kratz 《The European Physical Journal A - Hadrons and Nuclei》2002,13(3):281-284
Production yields and β-decay half-lives (T
1/2) of very neutron-rich indium isotopes were determined at CERN/ISOLDE using isobaric selectivity of a resonance-ionization
laser ion-source. Beta-delayed neutron (βdn) multiscaling measurements have yielded improved T
1/2 for 206(6) ms 132In, 165(3) ms 133In and 141(5) ms 134In. With 92(10) ms 135In, a new r-process nuclide has been identified which acts as an important “waiting point” in the In isotopic chain for neutron
densities in the range n
n≃ 1024-1026 n/cm3, where the r-matter flow has already passed the A≃ 130 abundance peak region.
Received: 17 January 2002 / Accepted: 30 January 2002 相似文献
14.
T. Beier H. Häffner N. Hermanspahn S. Djekic H.-J. Kluge W. Quint S. Stahl T. Valenzuela J. Verdú G. Werth 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):41-44
We describe a double-Penning-trap experiment suitable for testing QED in strong fields by determining the electronic g-factor of a single hydrogen-like ion in its ground state. Our measurements on 12C5 + reach a relative accuracy of 2×10-9, where the largest uncertainty results from the mass of the electron. Together with equally precise theoretical predictions
therefore, it is possible to evaluate a new value for the electron's mass. The possibilities to obtain other fundamental constants
and nuclear parameters are lined out.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: t.beier@gsi.de 相似文献
15.
S.W. Ødegård B. Herskind T. Døssing G.B. Hagemann D.R. Jensen G. Sletten J.N. Wilson S. Leoni P.O. Tjøm P. Bednarczyk D. Curien 《The European Physical Journal A - Hadrons and Nuclei》2002,14(3):309-316
High-spin properties of the triaxial strongly deformed potential well in 163Lu at excitation energies above resolvable bands have been investigated. Gated E
γ-E
γ spectra display clear ridges with moments of inertia corresponding to those observed for the discrete strongly deformed bands.
A fluctuation analysis of the ridges yields a number of two-step paths of ≈ 40 and ≈ 20, when gating on triaxial strongly
or normally deformed bands, respectively. These results show that a potential well at large deformation coexists with the
normally deformed well, and indicate a mixing between states in the two wells at higher excitation energy.
Received: 4 January 2002 / Accepted: 6 May 2002 相似文献
16.
M. Oba K. Akaoka M. Miyabe I. Wakaida 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(3):255-260
The laser induced fluorescence method using atomic beam combined with Doppler-free two-photon absorption technique was applied
for the measurement of isotope shifts and hyperfine structures of atomic uranium including 234U, 235U, 236U and 238U isotopes. The isotope shifts between 238U-234U, 238U-235U, 238U-236U, and the hyperfine structure of 235U were obtained in the high lying odd levels around 4 eV.
Received 3 December 2001 / Received in final form 4 July 2002 Published online 29 October 2002
RID="a"
ID="a"e-mail: oba@analchem.tokai.jaeri.go.jp 相似文献
17.
A new method for extracting the hyperfine anomaly from experimental hyperfine structure constants is suggested. Instead of
independent high-precision measurements of the nuclear magnetic dipole moment, precise measurements of magnetic dipole hyperfine
interaction constants for two atomic states and a theoretical analysis can be used. This can lead to determination of hyperfine
anomaly for radioactive isotopes where the nuclear magnetic dipole moment is not known with high accuracy.
Received: 17 February 1998 相似文献
18.
M. Koll R. Ricken D. Merten B.C. Metsch H.R. Petry 《The European Physical Journal A - Hadrons and Nuclei》2000,9(1):73-94
We present new results of a relativistic quark model based on the Bethe-Salpeter equation in its instantaneous approximation.
Assuming a linearly rising confinement potential with an appropriate spinorial structure in Dirac space and adopting a residual
interaction based on instanton effects, we can compute masses of the light mesons up to highest observed angular momenta with
a natural solution of the U
A(1) problem. The calculated ground states masses and the radial excitations describe the experimental results well. In this
paper, we will also discuss our results concerning numerous meson decay properties. For processes like π+/K
+↦e
+υeγ and 0-↦γγ at various photon virtualities, we find a good agreement with experimental data. We will also comment on the form factors
of the K
?3 decay and on the decay constants of the π, K and η mesons. For the sake of completeness, we will furthermore present the electromagnetic form factors of the charged π
and K mesons as well as a comparison of the radiative meson decay widths with the most recent experimental data.
Received: 28 August 2000 / Accepted: 12 September 2000 相似文献
19.
R. Lucas M.-G. Porquet Ts. Venkova I. Deloncle M. Houry Ch. Theisen A. Astier A. Bauchet S. Lalkovski G. Barreau N. Buforn T.P. Doan L. Donadille O. Dorvaux J. Durell Th. Ethvignot B.P.J. Gall D. Grimwood W. Korten Y. Le Coz M. Meyer A. Minkova A. Prévost N. Redon A. Roach N. Schulz A.G. Smith O. Stézowski B.J. Varley 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):315-323
The 115, 117, 119, 121In nuclei have been produced as fission fragments in three reactions induced by heavy ions: 12C + 238U at 90MeV bombarding energy, 18O + 208Pb reaction at 85MeV, and 31P + 176Yb at 152MeV. Their level schemes have been built from gamma-rays detected using the EUROBALL III and IV arrays. High-spin
states of 117, 119, 121In nuclei have been identified for the first time. Moreover, isomeric states lying around 2.5MeV have been established in
119, 121In from the delayed coincidences between the fission fragment detector SAPhIR and the gamma array. Most of the observed states
can be described by coupling a proton g
9/2 hole to a Sn core, while the intruder band based on an orbital from the π[g
7/2/d
5/2] sub-shells behaves as the ground-state band of neighbouring Cd isotopes.
Received: 24 May 2002 / Accepted: 11 June 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: porquet@csnsm.in2p3.fr
RID="b"
ID="b"Present address: CEA-DIF, DAM/DCRE/SDE/LDN, 91680 Bruyères-le-Chatel, France.
RID="c"
ID="c"Present address: CSNSM IN2P3-CNRS and Université Paris-Sud 91405 Orsay, France.
RID="d"
ID="d"Present address: CEA/Saclay, DSM/DAPNIA/SPhN, 91191 Gif-sur-Yvette Cedex, France.
Communicated by D. Schwalm 相似文献
20.
E. Bertin P. Bonville J.-P. Bouchaud J.A. Hodges J.P. Sanchez P. Vulliet 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,27(3):347-354
Using 155Gd M?ssbauer spectroscopy down to 27 mK, we show that, in the geometrically frustrated pyrochlore Gd2Sn2O7, the Gd3+ hyperfine levels are populated out of equilibrium. From this, we deduce that the hyperfine field, and the correlated Gd3+ moments which produce this field, continue to fluctuate as T
↦ 0. With a model of a spin 1/2 system experiencing a magnetic field which reverses randomly in time, we obtain an analytical
expression for the steady state probability distribution of the level populations. This distribution is a simple function
of the ratio of the nuclear spin relaxation time to the average electronic spin-flip time. In Gd2Sn2O7, we find the two time scales are of the same order of magnitude. We discuss the mechanism giving rise to the nuclear spin
relaxation and the influence of the electronic spin fluctuations on the hyperfine specific heat. The corresponding low temperature
measurements in Gd2Ti2O7 are presented and discussed.
Received 17 October 2001 Published online 6 June 2002 相似文献