Search results for "nuclear physics"
showing 10 items of 5307 documents
Nuclear Data Sheets for A=188
2018
Abstract Evaluated nuclear structure and decay data for all nuclei with mass number A=188 (Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po) are presented. The experimental data are compiled and evaluated, and best values for level and gamma-ray energies, quantum numbers, lifetimes, gamma-ray intensities, and other nuclear properties are recommended. Inconsistencies and discrepancies that exist in the literature are noted. This work supersedes the earlier evaluation by Balraj Singh (2002Si10), published in Nuclear Data Sheets 95, 387 (2002). The gamma-ray transition probabilities were calculated using the ENSDF analysis program ruler ( www-nds.iaea.org/public/ensdf_pgm/ ). However, the…
Mass measurements and ion-manipulation techniques applied to the heaviest elements
2016
NS160, Bäckaskog, Sweden, 29 May 2016 - 3 Jun 2016; The European physical journal / Web of Conferences 131, 05003 (2016). doi:10.1051/epjconf/201613105003
Neutrino masses, Majorons, and muon decay
1987
5 páginas, 3 figuras.
Tritium sorption and desorption from JET beryllium tiles under temperature, electron radiation and magnetic field
2008
Abstract Tritium release at annealing of samples cut from beryllium tiles exposed to D + D, D + T plasma in the Joint European Torus (JET) was investigated under 5 MeV fast-electron radiation at the dose rate 14 MGy h −1 and in a magnetic field of 1.7 T separately and simultaneously in order to evaluate possible effects of these factors. Abundances of chemical forms of tritium—molecular T 2 (44%), atomic T 0 (42%), and ionic T + (14%) and their distribution were determined in the plasma-exposed beryllium samples with lyomethods. Fast-electron radiation considerably increased the fractional tritium release at annealing by a factor of approximately 5. The magnetic field increased the fraction…
Isotope shift and hyperfine structure of stable platinum isotopes
1987
Isotope shift (IS) and hyperfine structure (hfs) measurements have been performed on seven lines of the platinum I spectrum with interference as well as laser fluorescence spectroscopy. In the latter case a frequency-doubled single-mode cw dye laser was applied. The IS of190Pt with a natural abundance of only 0.01% was determined to beδν 190, 192=−38.65(8) mK in theλ306.47 nm transition. The IS parameters and the effective hfs integrals in the configuration (5d+6s)10 were determined in intermediate coupling by a least squares fit of the IS and hfs data with eigenvectors obtained from the platinum fine structure (fs). The results are compared with theoretical values and yield improvedδ〈r 2〉 …
First experimental results of a cryogenic stopping cell with short-lived, heavy uranium fragments produced at 1000 MeV/u
2013
A cryogenic stopping cell (CSC) has been commissioned with U-238 projectile fragments produced at 1000 MeV/u. The spatial isotopic separation in flight was performed with the FRS applying a monoenergetic degrader. For the first time, a stopping cell was operated with exotic nuclei at cryogenic temperatures (70 to 100K). A helium stopping gas density of up to 0.05mg/cm(3) was used, about two times higher than reached before for a stopping cell with RF ion repelling structures. An overall efficiency of up to 15%, a combined ion survival and extraction efficiency of about 50%, and extraction times of 24ms were achieved for heavy a-decaying uranium fragments. Mass spectrometry with a multiple-r…
Neutronic and photonic analysis of the single box water-cooled lithium lead blanket for a DEMO reactor
1998
Abstract The water-cooled Pb–17Li demonstration plant (DEMO) breeding blanket line was selected in 1995 as one of the two EU lines to be further developed in the next decade. In this paper the results of a neutronic and photonic analysis of the `single box' concept is presented. A full three-dimensional model, including the whole assembly and many of the DEMO reactor components, has been developed, together with a three-dimensional neutron source. A tritium breeding ratio (TBR) value of 1.16, with no ports and a Li6 enrichment of 90%, has been obtained and a further analysis has been performed to determine Li6 enrichment that would still ensure tritium breeding self-sufficiency. Selected po…
The laser ion source trap for highest isobaric selectivity in online exotic isotope production
2010
The improvement in the performance of a conventional laser ion source in the laser ion source and trap (LIST) project is presented, which envisages installation of a repeller electrode and a linear Paul trap/ion guide structure. This approach promises highest isobaric purity and optimum temporal and spatial control of the radioactive ion beam produced at an online isotope separator facility. The functionality of the LIST was explored at the offline test separators of University of Mainz (UMz) and ISOLDE/CERN, using the UMz solid state laser system. Ionization efficiency and selectivity as well as time structure and transversal emittance of the produced ion beam was determined. Next step aft…
An on-line mass separator for fission-produced alkali isotopes
1980
Abstract The design of an on-line mass separator installed at the TRIGA reactor in Mainz is described and its performance discussed. A tungsten oven, filled with about 2 g of 235U embedded in graphite, is exposed to a flux of 1.7 × 1011 thermal neutrons (s− cm−2) near the reactor core. After diffusion out of the graphite the fission-produced alkali isotopes are surface-ionized and electromagnetically mass-separated, the resolving power being about 750. Losses during the diffusion out of the target material are discussed. Due to these losses the maximum separator efficiency is about 5%, corresponding to a source strength of about 109 particles s−1 for the most abundant isotopes. The heaviest…
Behaviour of tritium in breeding materials
2005
Abstract The tritium release from ceramic materials of the HCPB under real DEMO operating conditions will depend not only on temperature and neutron flux but also on an intense magnetic field (MF) of 7–9 T. The delay in the tritium release induced by the MF is proportional to the grain size of the ceramics, the squared MF intensity and the abundance ratio of charged tritium forms (T + , T − ) in the grain volume of the ceramics. The effect of MFs of different intensity on the tritium release from the Li 4 SiO 4 pebbles irradiated in the EXOTIC-8 experiment (neutron fluence 2.4 × 10 25 n m −2 , irradiation temperature up to 700 K) was investigated in this study. As a result of the irradiati…