Radiative Lifetimes and Oscillator Strengths for Allowed Transitions in Li-like and Be-like Si

Abstract

The lifefimes of the (2p)2 P 3/2 level in Si XII and the (2p 2)3 P 2,1,0, (2s2p)1 P 1 and the (2p 2)1 D 2 levels in Si XI have been determined using the beam-foil method. It is proposed that existing discrepancies between experimental and theoretical f values for the (2s 2)1 S 0-(2s2p)1 P 1 transition in some ions of the Be sequence may be the result of the inability of the experimentalist to account for strong cascading from the (2p 2)1 S 0 level.

EUV Spectrum and Lifetimes of Foil-Excited Phosphorus

“…111, and C1 [ 12. 131 are now available. Until recently only low ionization stages of phosphorus have been studied [14-161. Recent data by Pegg [9] contain 3 lifetimes of P XI1 states, but are quoted with less accuracy than, e.g., the Si data obtained by the same group [ 6 ] . The values for phosphorus agree with the Bochurn data for silicon [ 5 ] if scaled with l / Z to account for the variation along the isoelectronic sequence [17].…”

“…EUV spectra and lifetime data of few-electron ions of Mg [ l ] , A1 [ 2 ] . Si [3-81. P [9]. S [ 10.…”

Beam-Foil Lifetimes of Be-like Ions of Elements from Mg to S

“…340 [27] 59 [27] 64 [20] 86 [27] 75 [23] 87 [20] 84 [24] 668 [27] 700 [23] 750 [20] 704 [ 241 129 [27] 145 [20] 141 [24] 68 [27] 83 [20] 95 [27] 96 [20] 94 [24] 169 [27] 185 [20] 65 [27] 72 I201 755 [27] 830 [20] 800 [24] 27 [31] Table I 156 [23] 155 [24] 42 [27] 50 [20] 106 [27] 101 [26] 97 [23] 108 [20] 106 [24] 73 [27] 79 [27] 79 [20] 95 [20] 760 [9] 870 [27] 935 [26] 890 [23] 917 [24] 158 [27] 177 [20] 172 [24] 119 [27] 120 [24] 210 [27]…”

“…Particularly in the decay of the SXI(C-like) 2s2p3 ' 0 ' level, slow and strong out-of-shell cascades (e.g., the decay of the 2s22p3p 3D level, see [15,28] appear and have to be taken into account. [27] 29 [20] 150 [13] 410 [13] 190 [13] 90 [13] 49 [27] 117 [27] 135 [20] 49 [27] 117 [27] 135 [20] 34 [27] 40 [20] 117 [27] 116 [23] 132 [ 201 128 [24] 154 [27] 208 [21] 191 [20] 340 [27] 23 [27] 29 [20] 129 [27] 146 [20] 296 [27] 365 (211 340 (201…”

Beam-Foil Lifetime Studies of Highly Ionized Silicon

“…Cascade contributions to the decay of the singly excited ' Pp state are very strong. An insufficient allowance for cascades in the analysis of the decay curve easily causes lifetime errors as large as 100% (see also [16]). Our result, (155 t lO)ps, has been reported in [ 5 ] and agrees well with the theory [17].…”