Search results for "Short lived isotopes"
showing 4 items of 4 documents
Gas phase synthesis of 4d transition metal carbonyl complexes with thermalized fission fragments in single-atom reactions
2021
Abstract The formation of carbonyl complexes using atom-at-a-time quantities of short-lived transition metals from fusion and fission reactions was reported in 2012. Numerous studies focussing on this chemical system, which is also applicable for the superheavy elements followed. We report on a novel two-chamber approach for the synthesis of such complexes that allows spatial decoupling of thermalization and gas-phase carbonyl complex synthesis. Neutron induced fission on 235U and spontaneous fission of 248Cm were employed for the production of the fission products. These were stopped inside a gas volume behind the target and flushed with an inert-gas flow into a second chamber. This was fl…
First absolute mass measurements of short-lived isotopes
1987
Absolute mass measurements of short-lived isotopes have been performed at the on-line mass separator ISOLDE at CERN by determining the cyclotron frequencies of ions confined in a Penning trap. The cyclotron frequencies for77,78,85,86,88Rb and88Sr ions could be determined with a resolving power of 3×105 and an accuracy of better than 10−6, which corresponds to 100 keV for massA=100. The shortest-lived isotope under investigation was77Rb with a half-life of 3.7 min. The resonances obtained for the isobars88Rb and88Sr were clearly resolved.
Comparison between Theoretical Predictions and Legri Background Noise Experimental Measurements
2001
Trapped protons are responsible for the main component of LEGRI background. Detailed theoretical model has demonstrated that the proton-induced counting rate is two orders of magnitude larger than the counting rate of the diffuse gamma-ray flux. The continuous passes of LEGRI through the SAA (7 times everyday) makes very difficult the background modelling. Long and short lived isotopes contribute in very different time scales to the proton-induced background component. The goal of this paper is to present a comparison between the long-lived background noise theoretical predictions and the experimental data. The results show an unexpected good agreement between the predicted and the observed…
Precision Test of Many-Body QED in theBe+2pFine Structure Doublet Using Short-Lived Isotopes
2015
Absolute transition frequencies of the $2s\text{ }{^{2}S}_{1/2}\ensuremath{\rightarrow}2p\text{ }{^{2}P}_{1/2,3/2}$ transitions in ${\mathrm{Be}}^{+}$ were measured for the isotopes $^{7,9--12}\mathrm{Be}$. The fine structure splitting of the $2p$ state and its isotope dependence are extracted and compared to results of ab initio calculations using explicitly correlated basis functions, including relativistic and quantum electrodynamics effects at the order of $m{\ensuremath{\alpha}}^{6}$ and $m{\ensuremath{\alpha}}^{7} \mathrm{ln} \ensuremath{\alpha}$. Accuracy has been improved in both the theory and experiment by 2 orders of magnitude, and good agreement is observed. This represents on…