0000000000877905
AUTHOR
H. Hyvönen
Submillisecond On-Line Mass Separation of Nonvolatile Radioactive Elements: An Application of Charge Exchange and Thermalization Processes of Primary Recoil Ions in Helium
Transportation of thermalized primary recoil ions from nuclear reactions by helium flow has been investigated as a means of injecting short-lived radioactive nuclides into an on-line isotope separator. Several short-lived radioactive isotopes of highly nonvolatile elements such as B, Sc, Nb, and W have been separated. The efficiency for heavy nuclides with half-lives above 1 ms is between 1 and 10%. The shortest-lived activity identified in an on-line separation is the 182-\ensuremath{\mu}s isomeric state in $^{207}\mathrm{Bi}$.
Half-life and configuration of the 1/2+ intruder state in203Bi
The decay properties of theJπ=1/2+,Eexc=1,098 keV state in203Bi were studied. The state was populated via the204Pb(p, 2n) reaction and the activity was studied with the ion guide isotope separator on-line system IGISOL. The half-life of the 1/2+ state was measured to beT1/2=303 ±5 ms. From this value the partial half-lives of the three depopulating branches 1/2+ →7/2− (E3), 1/2+→5/2− (E3 +M2) and 1/2+→9/2 g.s. − (M4) were deduced. Since all the transitions are configuration forbidden in first order, a detailed study of second-order shell-model configuration mixing could be performed.