Beam-foil lifetime measurements of low-lying levels in Si IV

Abstract

New measurements of the radiative lifetimes of 3p, 3d, and 4s levels in Na-like Si IV have been made by fast ion beam excitation by a thin foil. Both curve fitting and ANDC joint decay curve analysis methods have been applied. The measured mean-life values (in ns) are: τ(3 p 2 P 1 2 )=1.16(5) ; τ(3 p 2 P 3 2 )=1.14(5) ; τ(3 d 2 D 3 2 )=0.42(5) ; τ(3 D 2 D 5 2 )=0.45(5) ; τ(4 s 2 S 1 2 =0.31(4) . The results confirm isoelectronic trends established by cascade-free laser excited measurements in lower charge states and other ANDC measurements in higher charge states, and resolve discrepancies with earlier studies that used multiexponential curve fitting reduction methods.