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1.
M. Drewsen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):125-127
We briefly discuss some possibilities for cooling, identification and spectroscopy of super-heavy element (SHE) ions based
on recent results obtained from studies of atomic and molecular ions in linear rf traps. Since these investigations only relied
on the charge and the mass of the ion of interest, we believe it should be straight forward to adopt most of the techniques
for SHE ion research. 相似文献
2.
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
3.
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
4.
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
5.
R. Bol N. J. Ostle C. Friedrich W. Amelung I. Sanders 《Isotopes in environmental and health studies》2013,49(1-2):97-109
Abstract Understanding the carbon (C) cycle in grassland pasture systems requires more information about the fate of decomposing dung material within the soil. In this soil lysimeter study we successfully applied the natural 13C abundance labelling technique to trace dung-C within a temperate grassland soil. Dung was collected from beef steers fed on either maize (a C4 plant) or perennial ryegrass (a C3 plant) silages, and applied to a freely draining (C3) grassland soil. Leachates were collected from soil lysimeters (0–2.5) and (0–10 cm soil depth) to determine the organic carbon and 13C content of < 0.7 μm filtered solution. Leachates were taken from (i) control, no dung added, (ii) C3 dung and (iii) C4 dung amended soil. Results showed that, (i) the addition of dung resulted in a tenfold increase in C lost from the lysimeters in drainage waters, (ii) up to 50% of the C present in the leachates was ‘native’ soil C and (iii) the application of dung produced a ‘priming’ effect. Further work is required to verify; (i) whether increased leaching of native C following dung application is a ‘true priming’ phenomenon, or merely the result of ‘displacement’ or ‘pool substitution’ of soil C, and (ii) the precise conditions and mechanisms under which organic amendments induce a true ‘priming’ effect in grassland and other agricultural soils. 相似文献
6.
Selected silty “summer” and argillaceous “winter” layers of profiles of the rhythmically bedded glacio-lacustrine ice-marginal lake sediment of the Dehlitz-Leipzig varved clay (Leipziger Tieflandsbucht, Central Germany) have been examined for isotope composition (18O/16O, 13C/12C) of carbonate and organic fraction. In addition, mineralogical and grain size compositions were determined. The results show 1) a change in source of carbonate sediment (provenance) through time; 2) the oxygen isotope ratios differed between the “summer” and “winter” layers of varves couplets due to different rates of sedimentation; 3) anoxic events occurred in the lake; 4) carbon isotope ratios suggest organics in lake sediments which were derived from land and the primary productivity was low in the lake itself. In the study of cold-climatic lake sediments, isotope investigations can efficiently be used as additional paleosedimentological and facies indicators. 相似文献
7.
B. Boag R. Neilson D. Robinson C. M. Scrimgeour L. L. Handley 《Isotopes in environmental and health studies》2013,49(1-2):81-85
Abstract We report the first isotopic study of an animal host-parasite system. Parasitic, intestinal nematodes, Graphidium strigosum and Passalurus ambiguus, were 15N-enriched relative to their host, the European rabbit Oryctolagus cuniculus, while parasitic cestodes, Cittataenia denticulata and Mosgovoyia pectinata, were 15N-depleted, suggesting different trophic relationships. Host embryos were more similar in their δ13C and δ15N values to maternal muscle than were any of the parasites. Coprophagy, the direct recycling of food by the rabbit eating its own faeces, did not lead to isotopic differences between stomach contents and faeces, suggesting that the major point for isotopic discrimination in lagomorph nitrogen metabolism is in the animal rather than in the gut. We conclude that bulk δ13C and δ15N can reveal valuable new information about host-parasite relationships, and these could be explored further at the biochemical level using compound-specific isotopic analyses. 相似文献
8.
Alan C. Calder Brendan K. Krueger Aaron P. Jackson Dean M. Townsley 《Frontiers of Physics》2013,8(2):168-188
Type Ia supernovae are bright stellar explosions distinguished by standardizable light curves that allow for their use as distance indicators for cosmological studies. Despite the highly successful use of these events in this capacity, many fundamental questions remain. Contemporary research investigates how properties of the progenitor system that follow from the host galaxy such as composition and age influence the brightness of an event with the goal of better understanding and assessing the intrinsic scatter in the brightness. We provide an overview of these supernovae and proposed progenitor systems, all of which involve one or more compact stars known as white dwarfs. We describe contemporary research investigating how the composition and structure of the progenitor white dwarf systematically influences the explosion outcome assuming the progenitor is a single white dwarf that has gained mass from a companion. We present results illustrating some of these systematic effects from our research. 相似文献
9.
A new improved nuclear partition function is employed to calculate
the nuclear statistical equilibrium (NSE) in core-collapse supernova
environment. The results show that the change of nucleus abundance
is slight even though the temperature is higher than 10$^{11}$\,K
when shock propagates, which indicates that the effect of the
nuclear partition function is not so important as shown in the
previous calculations, but it can also be considered in detailed
simulation if it is sensitive to weak interaction rates in
core-collapse supernova. 相似文献
10.
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