Autoionizing states in Li i observed in optical-emission spectra

Abstract

A beam-foil study of the lithium spectrum above 5000 A has been undertaken. Four new observations of core-excited doublet transitions are reported. All of these transitions have autoionizing states as the final state. The autoionization width of the (1s 2s S)3d~D has been measured, yielding a value of 0.89+0.04 meV. A comparison with calculations of the term energies and the width is presented.

Highly Efficient Continuous-Wave Laser Oscillation in Microchip Yb:YAG Laser at Room Temperature

“…In order to distinguish the probable manifestation of both processes in the measured excitation functions we have compared the energy positions of structures a-h with respect to the set of autoionizing levels which may combine radiatively with the investigated 2 S, 4 P, ( 3 P) 2 P and ( 1 P) 2 P levels (see figure 3). As one can see, the (1s2p 2 ) 4 P level at 60.75 eV and (1s2p 2 ) 2 P level at 61.61 eV are the nearest upper levels connected via the radiative transitions with the (1s2s2p) 4 P 1/2,3/2 and 1s(2s2p 3 P) 2 P levels Cederquist 1983, Cederquist andMannervik 1985). Therefore, process (1) may influence the excitation of these levels only at the impact energies above 60.75 eV.…”

“…Some contribution to the cross-section in the region of features g, h could also give the cascade transitions from the high-lying 1s2snd 4 D, (n = 3-5) and 1s2s5s 4 S levels (Mannervik and Cederquist 1983). In the excitation function for the 1s(2s2p 3 P) 2 P level (see figure 2) the feature f at 62.0 eV can be, at least partially, associated with the cascade transition (4585 Å) from the 1s2p 2 2 P level at 61.61 eV (Cederquist and Mannervik 1985). To our knowledge no radiative transitions are known into the (1s2s 2 ) 2 S and 1s(2s2p 1 P) 2 P autoionizing levels in lithium.…”

“…In lithium atoms this process is very effective (see e.g. Cederquist 1983, Cederquist andMannervik 1985). The second process is the Rassi et al (1977), Mannervik and Cederquist (1983), Yang and Chung (1995).…”

“…Letters a-h denote the energy positions of features observed in the measured excitation functions. Lines without arrows indicate the known radiative transitions Cederquist 1983, Cederquist andMannervik 1985). Lines with arrows indicate the possible decay channels for resonances a-h.…”

Calculation of the Lowest Resonant States of H− and Li by the Complex Absorbing Potential Method

“…The accuracy of the proposed approaches can be compared only for the lowest resonances N − 2 ( 2 Π g ) and CO − ( 2 Π), although simple systems (H − , He − , Li, etc.) could be used as test systems, for which the positions of the resonances are known with sufficient accuracy [48][49][50][51][52][53][54].…”