共查询到20条相似文献,搜索用时 15 毫秒
1.
D. Rudolph D.G. Sarantites C. Andreoiu C. Fahlander D.P. Balamuth R.J. Charity M. Devlin J. Eberth A. Galindo-Uribarri P.A. Hausladen D. Seweryniak L.G. Sobotka Th. Steinhardt 《The European Physical Journal A - Hadrons and Nuclei》2002,14(2):137-146
Prompt proton decay lines in 58Cu have been studied by means of high-resolution in-beam particle-γ coincidence spectroscopy using the GAMMASPHERE Ge-detector
array in conjunction with a dedicated set of ancillary detectors including four ΔE-E silicon-strip telescopes. High-spin states in 58Cu have been populated via the heavy-ion fusion-evaporation reaction 28Si(36Ar, 1α1p1n) at 148 MeV beam energy. The full-width at half maximum for the proton peak could be reduced significantly compared
to earlier experiments. The results indicate that only one prompt proton decay branch exists in the decay-out of the well-deformed
band of 58Cu.
Received: 11 March 2002 / Accepted: 10 April 2002 相似文献
2.
Yu.Ts. Oganessian V.K. Utyonkov Yu.V. Lobanov F.Sh. Abdullin A.N. Polyakov I.V. Shirokovsky Yu.S. Tsyganov G.G. Gulbekian S.L. Bogomolov B.N. Gikal A.N. Mezentsev S. Iliev V.G. Subbotin A.M. Sukhov O.V. Ivanov G.V. Buklanov K. Subotic A.A. Voinov M.G. Itkis K.J. Moody J.F. Wild N.J. Stoyer M.A. Stoyer R.W. Lougheed C.A. Laue 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):201-204
This paper presents results of the experiments aimed at producing long-lived superheavy elements located near the spherical-shell
closures with Z ⩾ 114 and N ⩾ 172 in the 244Pu + 48Ca and 248Cm + 48Ca reactions. The large measured α-particle energies of the newly observed nuclei, together with the long decay times and
spontaneous fission terminating the chains, offer evidence of the decay of nuclei with high atomic numbers. The decay properties
of the synthesized nuclei are consistent with the consecutive α-decays originating from the parent nuclides 288, 289114 and 292116, produced in the 3n and 4n evaporation channels with cross-sections of about a picobarn. The present observations can be considered as experimental
evidence of the existence of the “island of stability” of superheavy elements.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: utyonkov@sungns.jinr.ru 相似文献
3.
T. Bäck B. Cederwall K. Lagergren R. Wyss A. Johnson P. Greenlees D. Jenkins P. Jones D.T. Joss R. Julin S. Juutinen A. Keenan H. Kettunen P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku P. Nieminen J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2003,17(1):1-5
The decay out of the πh
11/2νh
11/2 band to the known low-energy levels in 132La was studied using the reaction 100Mo + 36S at 160 MeV beam energy. The low-energy level scheme has been further developed and unambiguous spin and parity values have
been assigned to the levels connecting the band to the 6- isomeric state. According to the new level scheme the spins in the πh
11/2νh
11/2 band are shifted up by one unit compared to the earlier tentative experimental values. The obtained new spins prove the existence
of signature inversion in 132La and give further support to the spin assignments made for the πh
11/2νh
11/2 bands in the neighbouring odd-odd La isotopes from level energy systematics.
Received: 7 May 2002 / Accepted: 31 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: timar@atomki.hu
RID="b"
ID="b"Present address: Dipartimento di Matematica e Fisica, Università di Camerino, via Madonna delle Carceri, I-62032 Camerino, Italy.
Communicated by J. ?yst? 相似文献
4.
E. Mergel C.M. Petrache G. Lo Bianco H. Hübel J. Domscheit D. Roßbach G. Schönwaßer N. Nenoff A. Neußer A. Görgen F. Becker E. Bouchez M. Houry A. Hürstel Y. Le Coz R. Lucas Ch. Theisen W. Korten A. Bracco N. Blasi F. Camera S. Leoni F. Hannachi A. Lopez-Martens M. Rejmund D. Gassmann P. Reiter P.G. Thirolf A. Astier N. Buforn M. Meyer N. Redon O. Stezowski 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):417-420
The even-even nucleus 136Nd was studied via in-beam γ-ray spectroscopy using the 16O + 125Te reaction at 100 MeV and the EUROBALL array. One new dipole band was observed. Together with a previously identified dipole
band, whose position in the level scheme is revised, the new band forms a doublet structure similar to the recently observed
chiral bands in the odd-odd neighboring nuclei. This would be the first case of a chiral doublet in an even-even nucleus.
Received: 23 May 2002 / Accepted: 30 September 2002 / Published online: 27 November 2002
RID="a"
ID="a"e-mail: costel.petrache@unicam.it
RID="b"
ID="b"Present address: Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
RID="c"
ID="c"Present address: Gesellschaft für Schwerionenforschung D-64291 Darmstadt, Germany.
Communicated by C. Signorini 相似文献
5.
B. Blank 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):121-124
In recent experiments at GANIL, we studied nuclei at the one- and two-proton drip line. The production rates allowed to search
for direct 2p emission in the drip line nuclei 42Cr, 45Fe, and 49Ni. No evidence for this decay mode was found in 42Cr and 49Ni, whereas the situation stays unclear for 45Fe due to the limited statistics. In the medium-mass region ( A = 50-70), the half-life was measured for all proton-rich nuclei in the range T
z = 0 to T
z = - 1 between Z = 27 and Z = 36. First half-lives were determined for 60Ga, 62Ge, 64As and 66Se. Finally, β-decay studies of the 0+ → 0+ decay of 62Ga have been performed at IGISOL in Jyv?skyl?. Non-analog transitions have been observed and are compared to theoretical predictions.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: blank@cenbg.in2p3.fr 相似文献
6.
M. Snels G. D'Amico 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(2):137-142
High resolution infrared spectra (0.001 cm-1) have been measured for mixtures of 1-chloro-1,1-difluoroethane in Ne, expanded in a supersonic planar jet. The ν
7
fundamental has been analyzed for both isotopic species, CH3CF2
35Cl and CH3CF2
37Cl. A weak b-type component has been observed for the first time.
Received 20 May 2002 / Received in final form 10 July 2002 Published online 24 September 2002
RID="a"
ID="a"Also: Dipartimento di Scienze Fisiche Universitá di Napoli “Federico II” Complesso Universitario di M.S. Angelo, 80126 Napoli,
Italy. e-mail: m.snels@isac.cnr.it 相似文献
7.
S. Witte E.J. van Duijn R. Zinkstok W. Hogervorst 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(2):159-164
With the second and third harmonic of a tunable single-mode cw Ti:S laser, generated inside external enhancement cavities,
high-resolution LIF measurements on several states of Lu I in various parts of the electromagnetic spectrum are performed.
From these measurements, hyperfine structure A and B constants for both 175Lu and 176Lu as well as isotope shifts have been determined for all levels observed in the single-step excitation process. From the
measured A constants, the magnetic hyperfine structure anomaly has been derived for various states.
Received 14 January 2002 Published online 19 July 2002 相似文献
8.
Vinod Kumar Pragya Das R.P. Singh S. Muralithar R.K. Bhowmik 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):153-157
The fusion evaporation reaction 122Sn(14N, 4n)132La was used to populate the high-spin states of 132La at the beam energy of 60 MeV. A new band consisting of mostly E2 transitions has been discovered. This band has the interesting links to the ground state 2- and the isomeric state 6-. A new transition of energy 351 keV connecting the low-spin states of the positive-parity band based on the πh
11/2 ⊗ νh
11/2 particle configuration, has been found. This has played a very important role in resolving the existing ambiguities and inconsistencies
in the spin assignment of the band head.
Received: 12 August 2002 / Accepted: 18 March 2003 / Published online: 7 May 2003 相似文献
9.
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
10.
J. A. Pomarico D. I. Iriarte H. O. Di Rocco 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(1):65-72
In this paper we analyze the variations in line intensities ratios due to a non-equilibrium situation and to optical depth
effects. A four level model is proposed and the two particular situations for the possible transitions are considered. Electron
density and temperature as well as the source thickness are used as independent parameters to find out in which way and extent
they modify the ratios of levels populations compared with the ideal case of an equilibrium state and optically thin source.
Accordingly with the ion of interest, electron temperatures ranging from I/20 to I/7 eV (I being the ionization energy), whereas electron densities in the interval from 1014 to 1020 cm-3 will be considered. These ranges are of special interest for diverse applications such as LIBS and measurement of transition
probabilities. Some results are presented for real ions and a new expression for the escape factor is also proposed for general
plasma conditions.
Received 12 June 2001 and Received in final form 24 October 2001 相似文献
11.
J. Kurpeta G. Lhersonneau A. Płochocki J.C. Wang P. Dendooven A. Honkanen M. Huhta M. Oinonen H. Penttilä K. Peräjärvi J.R. Persson J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2002,13(4):449-460
The decay of neutron-rich isotope 113Ru obtained as on-line mass separated product of proton-induced fission has been investigated by γγ coincidence and spectrum
multiscaling measurements. Decay schemes for both low- and high-spin isomers of 113Ru have been constructed. The level scheme of 113Rh is considerably extended. Systematics of the lowest-lying rhodium levels is smooth. The picture of shape coexistence established
for neutron-rich Rh isotopes near-neutron midshell is confirmed with the observation of a K = 1/2 deformed band, with its 3/2+ state at 600 keV being the lowest-lying level and of probable 7/2+
and 5/2+
band members. A large fraction of β feeding is found to populate high-lying levels in 113Rh. The GT strength in 113Rum decay is significantly larger than for the decay of 113Rug and of lighter rhodium isotopes.
Received: 18 January 2001 / Accepted: 14 January 2002 相似文献
12.
W. Urban J.A. Pinston T. Rzaca-Urban A. Złomaniec G. Simpson J.L. Durell W.R. Phillips A.G. Smith B.J. Varley I. Ahmad N. Schulz 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):11-15
A new band, populated by the spontaneous fission of 248Cm and studied by means of prompt γ-ray spectroscopy using the EUROGAM2 array, was observed in 99Zr. The 1038.8 keV band head with a half-life T
1/2 = 54(10) ns is interpreted as a K-isomer, corresponding to the 9/2[404] neutron-hole excitation. It is the first observation of this orbital in the mass A ∼ 100 region. The quadrupole moment, Q
0 = 3.9(3) eb deduced for the new band indicates a large deformation of β = 0.41, which is produced by a specific shape-coexistence
mechanism, known in other regions and now found in the A ∼ 100 nuclei.
Received: 11 September 2002 / Accepted: 31 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: urban@fuw.edu.pl
Communicated by D. Schwalm 相似文献
13.
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
14.
G. Lhersonneau B. Pfeiffer J. Alstad P. Dendooven K. Eberhardt S. Hankonen I. Klöckl K.-L. Kratz A. Nähler R. Malmbeck J.P. Omtvedt H. Penttilä S. Schoedder G. Skarnemark N. Trautmann J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):285-297
The decay of 111Ru obtained from fast on-line chemical and mass separation has been investigated by β-γ-t and γ-γ coincidence techniques. Earlier spin and parity assignments of 111Rh levels based on extrapolations of level systematics are confirmed. In particular, the K=1/2 intruder band is supported
by the hindrance of E2 transitions between deformed and spherical states and enhancement of intraband E2 transitions. The
excitation energies of intruder band members in Rh isotopes show a minimum at 109Rh64, with two neutrons less than 111Rh at the N=66 midshell. This trend, which differs from the one in the higher-Z neighbouring elements Ag and Cd with minima
at N=66, follows the evolution of deformation observed in the lower-Z elements Ru and Mo.
Received: 25 June 1997 / Revised version: 10 September 1997 相似文献
15.
D. Jacquemart J.-Y. Mandin V. Dana N. Picqué G. Guelachvili 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):55-69
To deduce accurate infrared molecular line parameters (positions at zero pressure, pressure-shifting and pressure-broadening
coefficients, collisional narrowing coefficients, and intensities) from rovibrational spectra, an automatic method based upon
a multispectrum fitting procedure has been set up, able to treat simultaneously several laboratory Fourier transform spectra.
A validation of this method, using absorption spectra of the 3-0 vibrational band of CO around 6 350 cm-1, already used to measure line intensities and self-broadening coefficients, is presented, and the advantages of the method
are pointed out. The self-collisional narrowing of CO was observed and determined for the first time in Fourier transform
spectra: β
= 0.028±0.004 cm-1 atm-1 at about 296 K.
Received 21 September 2000 and Received in final form 15 January 2001 相似文献
16.
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
17.
A.A. Pasternak J. Srebrny A.D. Efimov V.M. Mikhajlov E.O. Podsvirova Ch. Droste T. Morek S. Juutinen G.B. Hagemann M. Piiparinen S. Törmänen A. Virtanen 《The European Physical Journal A - Hadrons and Nuclei》2002,13(4):435-448
Lifetimes of excited states in 118Te have been measured using the Doppler Shift Attenuation (DSA) and Recoil Distance (RD) methods in the 109Ag(13C, p3n) reaction at a beam energy of 54 MeV. Lifetime values of the ground-state band levels with spins I
π = 2+-16+ have been obtained. The excitation energies and B(E2) values are interpreted in the framework of a version of IBFM ( IBM + 2qp) with the maximum boson number exceeding its standard
value. A satisfactory agreement with experimental level scheme and B(E2) values for the ground-state band is achieved.
Received: 7 June 2001 / Accepted: 7 February 2002 相似文献
18.
S. Hofmann 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):195-200
The nuclear shell model predicts that the next doubly magic shell-closure beyond 208Pb is at a proton number between Z = 114 and 126 and at a neutron number N = 184. The outstanding aim of experimental investigations is the exploration of this region of spherical “Superheavy Elements”.
This article describes the experiments that were performed at the GSI SHIP. They resulted in an unambiguous identification
of elements 107 to 112. They were negative so far in searching for elements 113, 116 and 118 at SHIP; however, positive results
were reported from experiments in Dubna on elements 114 and 116 and from experiments in Berkeley on element 118. The measured
decay data are compared with theoretical predictions. Some aspects concerning the reaction mechanism and the use of radioactive
beams are also presented.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: S.Hofmann@gsi.de 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.
W. Urban T. Rzaca-Urban N. Schulz J.L. Durell W.R. Phillips A.G. Smith B.J. Varley I. Ahmad 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):303-307
Excited levels in 140Xe and 142Xe nuclei, populated in the spontaneous fission of 248Cm, were studied by means of prompt γ-ray spectroscopy, using EUROGAM2 array. We report the first observation of an octupole
band in 142Xe and extend the octupole band in 140Xe. Level schemes of 140Xe and 142Xe obtained in this work show patterns characteristic of ocupole-vibrational bands. Properties of octupole bands in Xe isotopes
indicate that octupole correlations in these nuclei are lower than in the corresponding Ba nuclei. The electric dipole moment
of 142Xe was found to be larger than in other Xe isotopes, contrary to theoretical predictions. This may be due to the special role
of the N = 88 neutron number.
Received: 18 November 2002 / Accepted: 15 December 2002 / Published online: 25 February 2003
RID="a"
ID="a"e-mail: urban@fuw.edu.pl
Communicated by D. Schwalm 相似文献