Photoionization from the Selectively Excited3s3pP11∘State to the3p2S01Autoionization Level of Mg i

Abstract

The $3s3p{{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}}^{\circ }$ level of Mg i has been selectively excited by the second harmonic of the output of a high-power, narrow-band, frequency tunable dye laser. The excited-state absorption series $3s3p{{}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}}^{\circ }-3\mathrm{snd}{}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ has been recorded to $n=24\mathrm{}$. A strong autoionization resonance has been obtained at $\lambda =300.9\mathrm{}$ nm, with a photoionization cross section of ∼5 × ${10}^{-16\mathrm{}}$ ${\mathrm{cm}}^2$, in very good agreement with the values predicted by calculation.