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1.
C. Scheidenberger 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):7-11
The present status and recent results from direct mass measurements of exotic nuclei are presented. ISOL, in-flight, and combined
facilities provide a wide variety of nuclides far-off stability covering a wide range of half-lives down to the sub-millisecond
region. Modern direct mass measurements are carried out using frequency and time-of-flight techniques. The obtained accurate
mass data point to nuclear-structure phenomena and serve as a basis for astrophysical and weak-interaction studies.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: c.scheidenberger@gsi.de 相似文献
2.
T. Fritioff C. Carlberg G. Douysset R. Schuch I. Bergström 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(2):141-143
The atomic and nuclear masses of 4He and 3He have been measured using doubly charged ions in a Penning trap connected to an electron beam ion source. Recent technical
improvements allow mass determinations with uncertainties of a few parts in 1010. The obtained atomic masses are 4.002 603 256 8(13) u and 3.016 029 323 5(28) u respectively. These values deviate by as
much as 5 standard deviations from the accepted values.
Received 23 October 2000 and Received in final form 6 February 2001 相似文献
3.
Progress is reviewed of available data for evaluation of atomic masses since the 1995 one. Many more direct mass measurements
have become available, especially in the region of proton-rich nuclides. The number of alpha- and, especially, proton-decay
data increased considerably. In the region of superhigh mass numbers, many very interesting new observations were made.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: wapstra@nikhef.nl 相似文献
4.
H. Backe P. Kunz W. Lauth A. Dretzke R. Horn T. Kolb M. Laatiaoui M. Sewtz D. Ackermann M. Block F. Herfurth F. P. Heßberger S. Hofmann R. Mann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):99-106
For the investigation of the atomic level structure of
heavy elements which can only be produced at on-line facilities
such as GSI, a novel experimental procedure has been developed. It
is based on Radiation Detected Resonance Ionization Spectroscopy
(RADRIS) and can be applied to elements like nobelium produced at
rates of a few ions per second. Fusion reaction products are
separated from the primary beam by the velocity filter SHIP at
GSI, stopped in a buffer gas cell, collected on a tantalum
filament and then re-evaporated as atoms. The ions produced by
resonance ionization with tunable laser beams are detected via
their characteristic α decay. First on-line experiments on
α-active 155Yb, which is supposed to have an atomic
level structure similar to nobelium, were performed. These test
experiments focused on the optimization of the collection and
re-evaporation process of the radioactive ions, the laser
ionization efficiency and the detection via α decay. An
overall efficiency for RADRIS of 0.8% with respect to the target
production rate was measured. While further improvements of this
efficiency are in progress it should already be sufficient for the
search for atomic levels in nobelium. 相似文献
5.
V. Pershina J. Anton T. Bastug 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):87-90
Interaction of superheavy element 112 and its homolog Hg
with inert and gold surfaces was studied on the basis of atomic
and molecular fully-relativistic (4-component) DFT electronic
structure calculations. Performance of additional non-relativistic
calculations allowed one to demonstrate the role and magnitude of
relativistic effects on adsorption energies and bond distances of
the studied systems. For example, on quartz, element 112 will be
stronger adsorbed than Hg by about 5 kJ/mol (or at 5 degrees
higher temperatures) due to the stronger van der Waals
interaction. This is caused by the relativistically contracted
smallest atomic radius of element 112. Non-relativistically, the
trend would be opposite. On surface of gold, element 112 will be
about 20 kJ/mol weaker adsorbed than Hg (i.e., it will be
deposited at about 100 degrees lower temperatures than Hg). Such a
decrease in ΔHads comes at the account of the weaker
interaction of the relativistically stabilized 7s1/2(112)
orbital with valence orbitals of gold. Still, the relatively large
adsorption energy of element 112 is indicative that it is a
transition metal forming intermetallic compounds with Au and other
metals due to the involvement of the relativistically destabilized
6d orbitals. The influence of relativistic effects on the
adsorption energy depends, however, on the adsorption position. 相似文献
6.
M. Mukherjee D. Beck K. Blaum G. Bollen P. Delahaye J. Dilling S. George C. Guénaut F. Herfurth A. Herlert A. Kellerbauer H. -J. Kluge U. Köster D. Lunney S. Schwarz L. Schweikhard C. Yazidjian 《The European Physical Journal A - Hadrons and Nuclei》2008,35(1):31-37
Frequency ratio measurements with different combinations of the singly charged ions from 21, 22, 23Na , 22, 24Mg , and 37, 39K were performed at the on-line Penning trap mass spectrometer ISOLTRAP, CERN, Geneva. The masses and mass differences were
deduced with a relative uncertainty of about or even below one part in 108 for the ions of interest using a least-squares analysis of all measured relations. The results have direct consequences for
weak-interaction study as they give additional input to the test of CVC, and for nuclear astrophysics, because they help to
establish the minimum observable signal for a NeNa cycle in a nova burst. We report here about the measurements and the detailed
evaluation. 相似文献
7.
Kellerbauer A. Blaum K. Bollen G. Herfurth F. Kluge H.-J. Kuckein M. Sauvan E. Scheidenberger C. Schweikhard L. 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(1):53-64
For a detailed study of the accuracy of the Penning trap mass spectrometer ISOLTRAP all expected sources of uncertainty were
investigated with respect to their contributions to the uncertainty of the final result. In the course of these investigations,
cross-reference measurements with singly charged carbon clusters 12C+
n were carried out. The carbon cluster ions were produced by use of laser-induced desorption, fragmentation, and ionization
of C60 fullerenes and injected into and stored in the Penning trap system. The comparison of the cyclotron frequencies of different
carbon clusters has provided detailed insight into the residual systematic uncertainty of ISOLTRAP and yielded a value of
8×10-9. This also represents the current limit of mass accuracy of the apparatus. Since the unified atomic mass unit is defined
as 1/12 of the mass of the 12C atom, it will be possible to carry out absolute mass measurements with ISOLTRAP in the future.
Received 7 June 2002 Published online 6 November 2002
RID="a"
ID="a"e-mail: a.kellerbauer@cern.ch
RID="b"
ID="b"Current address: Centre de Physique des Particules de Marseille, 13288 Marseille Cedex 9, France. 相似文献
8.
Sz. Nagy T. Fritioff A. Solders R. Schuch M. Björkhage I. Bergström 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(1):1-4
High-precision mass measurements on lithium-like and hydrogen-like 40Ca-ions are reported. The obtained mass of the hydrogen-like and lithium-like ion is 39.952181819(29) u and 39.953272223(24) u,
respectively. The corresponding mass of the 40Ca atom is 39.962590858(22) u. This new value has a precision ten times higher than the literature value. 相似文献
9.
H. Backe F. P. Heßberger M. Sewtz A. Türler 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):3-15
This article reviews the following topics which were discussed at the
375th Wilhelm and Else Heraeus-Seminar
Workshop on the Atomic Properties of the Heaviest Elements
held from September 25–27, 2006 at the Abtei Frauenw?rth im Chiemsee, Germany:
(i) the recent progress in the
production of the heaviest elements, the investigation of their
nuclear structure, and prospects for direct mass measurements in
Penning traps. (ii) Recent studies of their chemical
properties with the aid of volatile species and single-atom
aqueous-phase chemistry; (iii) the current status and future prospects for
the investigation of atomic and ionic properties such as
optical
spectroscopy in gas cells and ion traps, including fully
relativistic calculations of the atomic level structure with
predictions for the element nobelium; and (iv) ionic charge radii
measurements in buffer gas filled drift cells, and ion chemical
reactions in the gas phase. 相似文献
10.
M. Mukherjee D. Beck K. Blaum G. Bollen J. Dilling S. George F. Herfurth A. Herlert A. Kellerbauer H. -J. Kluge S. Schwarz L. Schweikhard C. Yazidjian 《The European Physical Journal A - Hadrons and Nuclei》2008,35(1):1-29
ISOLTRAP is a Penning trap mass spectrometer for high-precision mass measurements on short-lived nuclides installed at the
on-line isotope separator ISOLDE at CERN. The masses of close to 300 radionuclides have been determined up to now. The applicability
of Penning trap mass spectrometry to mass measurements of exotic nuclei has been extended considerably at ISOLTRAP by improving
and developing this double Penning trap mass spectrometer over the past two decades. The accurate determination of nuclear
binding energies far from stability includes nuclei that are produced at rates less than 100 ions/s and with half-lives well
below 100ms. The mass-resolving power reaches 107 corresponding to 10keV for medium heavy nuclei and the uncertainty of the resulting mass values has been pushed down to below
10-8. The article describes technical developments achieved since 1996 and the present performance of ISOLTRAP. 相似文献
11.
K. J. Öberg H. Lundberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(1):15-34
Radiative lifetimes of nine out of the twelve 4f136p levels in Yb III have been measured, seven of these for the first time. A Penning discharge lamp is introduced as a continuous
plasma source, in which the lifetimes are determined with the time-resolved laser-induced fluorescence technique by pumping
from metastable 5d and 6s levels. Spectra of the same source are recorded with a Fourier-transform spectrometer, which are
used to derive branching fractions of the 6p and 7s levels. Combined with the lifetimes, the branching fractions are used
to determine 81 experimental transition probabilities. Wavelengths of 142 Yb III transitions are measured and the uncertainties
of corresponding Ritz wavenumbers are improved by an order of magnitude from the prior values. The energy of the 5d (5/2,5/2)○
0 level has been shifted 144.20 cm-1 to the higher value 45421.045 cm-1. Much emphasis is put on data treatment and error analysis.
Electronic supplementary material Supplementary Online Material 相似文献
12.
J. Walls J. Clarke S. Cauchi G. Karkas H. Chen W.A. van Wijngaarden 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):9-13
Polarizabilities of several rubidium states were determined by measuring stark shifts of transitions using an electro-optically
modulated laser beam to excite an atomic beam. The voltage required for atoms excited by the laser beam in an electric field
to be simultaneously in resonance as atoms excited by a frequency sideband of the laser in a field free region was measured.
The scalar α
and tensor α
2
polarizabilities were found to be: α
(9
S
1/2
) = 103.77±0.09, α
(10
S
1/2
) = 272.54±0.16, α
(8
D
3/2
) = 230.68±0.25 and α
2
(8
D
3/2
) = 26.55±0.10, α
(8
D
5/2
) = 222.68±0.14 and α
2
(8
D
5/2
) = 51.91±0.10 MHz/(kV/cm)2. The results are 100 times more accurate than previous measurements and are within 1% of those found theoretically using
a Coulomb approximation calculation.
Received 7 September 2000 and Received in final form 6 December 2000 相似文献
13.
For the determination of the bound-electron g factor
in hydrogen-like heavy ions the mass of the ion is needed at a
relative uncertainty of at least 1 ppb. With the
SMILETRAP Penning trap mass spectrometer at the Manne
Siegbahn Laboratory in Stockholm several mass measurements of ions
with even-even nuclei at this level of precision have been
performed so far, exploiting the fact that the mass precision
increases linearly with the ion charge. Measurements of masses of
the hydrogen-like ions of the two Mg-isotopes 24Mg and
26Mg are reported. The masses of the hydrogen-like ions are
23.979011054(14) u and 25.976562354(34) u,
corresponding to the atomic masses 23.985041690(14) u and
25.982592986(34) u, respectively. The possibility to use
these two isotopes for the first observation of an isotope effect
in the bound-electron g factor in hydrogen-like heavy ions is
discussed. 相似文献
14.
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
15.
Doppler-free spectroscopy using magnetically induced dichroism of atomic vapor: a new scheme for laser frequency locking 总被引:3,自引:0,他引:3
T. Petelski M. Fattori G. Lamporesi J. Stuhler G.M. Tino 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(2):279-283
We demonstrate a Doppler-free spectroscopic method that we test on 87Rb and 85Rb vapor. By using a magnetic field to induce a dichroism on the sample, we generate a dispersive signal with low background,
which allows us to lock a diode laser even on small spectroscopic features. We elaborate the advantages of this simple and
easy method by comparing it to other methods.
Received 15 October 2002 Published online 17 December 2002 相似文献
16.
R. Ferrer K. Blaum M. Block F. Herfurth J. Ketelaer Sz. Nagy D. Neidherr C. Weber 《The European physical journal. Special topics》2007,150(1):347-348
The Penning-trap mass spectrometer SHIPTRAP at GSI is designed to provide clean and cooled beams of singly charged radioactive
ions produced in fusion-evaporation reactions and separated in-flight by the velocity filter SHIP. The scientific goals include
mass spectrometry, atomic and nuclear spectroscopy, and chemistry of transuranium species which are not available at ISOL-
or fragmentation facilities Penning-trap based mass measurements on radionuclides relies up to now on the destructive time-of-flight
ion-cyclotron-resonance method. One of the main limitations to the experimental investigations is the low production rate
of most of these exotic nuclides, for which the use of this detection scheme is not applicable. A sensitive and non-destructive
method, like the narrow-band Fourier Transform ion-cyclotron-resonance technique, is ideally suited for the identification
and characterization of these species. A new cryogenic trap setup for SHIPTRAP exploiting this detection technique as well
as some results of first preparatory tests are presented. 相似文献
17.
J. P. Omtvedt J. Alstad T. Bjørnstad Ch. E. Düllmann K. E. Gregorich D. C. Hoffman H. Nitsche K. Opel D. Polakova F. Samadani F. Schulz G. Skarnemark L. Stavsetra R. Sudowe L. Zheng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):91-97
This article starts with a review of the current SISAK liquid-liquid extraction system, as used after the physical preseparator
BGS at LBNL for chemical studies of transactinide elements. Emphasis will be on new additions and developments. Then the possibilities
offered by the new TASCA separator at GSI and the use of actinide targets at both GSI and LBNL are discussed with respect
to future SISAK transactinide experiments. Finally, current and future liquid-liquid extraction systems for studying elements
Rf up to Hs are discussed. 相似文献
18.
A. Türler 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):271-274
In the past ten years, nuclear chemists have made considerable progress in developing fast on-line separation techniques,
which allowed to chemically characterize the first four transactinide elements Rf (rutherfordium, Z = 104), Db (dubnium, Z = 105), Sg (seaborgium, Z = 106), and recently also Bh (bohrium, Z = 107). In all cases the isolated nuclides were unambiguously identified by observing genetically linked decay chains. Nuclides
with production cross-sections of less than 100 pb and half-lives as short as a few seconds have been chemically isolated.
Thus, chemists have discovered or significantly contributed to the characterization of the nuclear-decay properties of a number
of transactinide nuclei. New techniques with greatly improved overall efficiencies should allow chemists to extend their studies
to even heavier elements such as Hs (hassium, Z = 108) and to the recently discovered superheavy elements with Z = 112 and 114, which can be produced only with picobarn cross-sections.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: andreas.tuerler@psi.ch 相似文献
19.
A.I. Levon J. de Boer M. Loewe M. Würkner T. Czosnyka J. Iwanicki P.J. Napiorkowski 《The European Physical Journal A - Hadrons and Nuclei》1998,2(1):9-11
The E1 transition from the 3/2− state to the ground state of 229Pa was identified in the (p,tγ) reaction. Its energy is found to be 11.6(3) keV. This leads to a value of Qg.s.=−4133(2) keV and to a mass defect of 229Pa of 29894(3) keV. It is concluded that the ground-state configuration of 229Pa is 3/2[651].
Received: 29 January 1998 相似文献
20.
F.P. Heßberger S. Hofmann I. Kojouharov D. Ackermann S. Antalic P. Cagarda B. Kindler B. Lommel R. Mann A.G. Popeko S. Saro J. Uusitalo A.V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):335-342
The radioactive decay of 217Pa was investigated by means of α-γ-spectroscopy. Fine structure in the ground-state α-decay was established. Ambiguities
in the fine structure of the α-decay of the previously known isomeric state could be clarified by α-γ-coincidence measurements.
A previously unknown α-transition of E
α = (8306 ± 5) keV was detected and identified by means of delayed α-α- and α-γ-γ-coincidence measurements. A second isomeric
state decaying by α-emission was not observed. The quality of the previously reported data of the α-decay fine structure of
217Th was improved.
Received: 29 April 2002 / Accepted: 17 June 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: f.p.hessberger@gsi.de
Communicated by J. ?yst? 相似文献