Decay properties of the neutron-rich isotopes, Li 11 and Na</mml…
1974; American Institute of Physics; Volume: 10; Issue: 3 Linguagem: Inglês
10.1103/physrevc.10.1181
ISSN1538-4497
AutoresE. Roeckl, P. F. Dittner, C. Détraz, R. Klapisch, C. Thibault, C. Rigaud,
Tópico(s)Advanced Chemical Physics Studies
ResumoUsing an on-line mass spectrometer the decay properties of the ${T}_{z}\ensuremath{\ge}\frac{5}{2}$ nuclei $^{11}\mathrm{Li}$, $^{27\ensuremath{-}31}\mathrm{Na}$, $^{29,30}\mathrm{Mg}$ were studied. The new isotope $^{30}\mathrm{Mg}$ (${T}_{\frac{1}{2}}=1200\ifmmode\pm\else\textpm\fi{}500$ msec) identified by $\ensuremath{\beta}$ counting. For the other isotopes the half-lives were remeasured by three independent methods with improved precision. By recording $\ensuremath{\beta}$-coincident $\ensuremath{\gamma}$ spectra, the decays of $^{27\ensuremath{-}29}\mathrm{Na}$ were studied, leading to a ${1}^{+}$ assignment for the $^{28}\mathrm{Na}$ ground state. By simultaneous $\ensuremath{\beta}$ and neutron multiscaling the delayed neutron emission probabilities ${P}_{n}$ were determined for $^{11}\mathrm{Li}$ and $^{27\ensuremath{-}31}\mathrm{Na}$. The following half-lives (msec) and ${P}_{n}$ values (%) were found (errors see text): $^{11}\mathrm{Li}$ (8.5/60.8), $^{27}\mathrm{Na}$ (304/0.08), $^{28}\mathrm{Na}$ (30.5/0.58), $^{29}\mathrm{Na}$ (42.9/15.1), $^{30}\mathrm{Na}$ (53.0/33.1), $^{31}\mathrm{Na}$ (16.9/30).RADIOACTIVITY $^{9,11}\mathrm{Li}$, $^{27,28,29,30,31}\mathrm{Na}$, $^{29,30}\mathrm{Mg}$; measured ${T}_{\frac{1}{2}}$, ${E}_{\ensuremath{\beta}}$, $\ensuremath{\beta}\ensuremath{\gamma}$ coin, delayed neutrons; deduced ${E}_{\ensuremath{\gamma}}$, ${I}_{\ensuremath{\gamma}}$, $log\mathrm{ft}$, $Q$, $J$, $\ensuremath{\pi}$, ${P}_{n}$. On-line mass separation.
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