Measurement of metastable lifetimes for transitions inFe9+,Fe10+, andFe13+

Abstract

Radiative lifetimes are measured for metastable levels in the iron charge states ${\mathrm{Fe}}^{9+},{\mathrm{Fe}}^{10+}$, and ${\mathrm{Fe}}^{13+}$. The ions are generated in a 14 GHz electron cyclotron resonance ion source and trapped in a Kingdon ion trap. The Fe levels and their measured lifetimes are (a) $73.0\ifmmode\pm\else\textpm\fi{}0.8\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$ for the $3{s}^{2}3{p}^{4}(^{3}P)3d$ $^{4}F_{7∕2}$ level in ${\mathrm{Fe}}^{9+}$, (b) $9.91\ifmmode\pm\else\textpm\fi{}0.5\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$ for the $3{s}^{2}3{p}^{4}$ $^{1}D_{2}$ level in ${\mathrm{Fe}}^{10+}$, and (c) $17.0\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$ for the $3{s}^{2}3p$ $^{2}P^{o}_{3∕2}$ level in ${\mathrm{Fe}}^{13+}$. Comparisons are made to other measured results using a Kingdon trap, an ion storage, and an electron-beam ion trap (EBIT).