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arXiv · 1909.12689

The spin-forbidden vacuum-ultraviolet absorption spectrum of 14N15N

A. N. Heays·B. R. Lewis·N. de Oliveira·W. Ubachs
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Abstract

Photoabsorption spectra of ${}^{14}{\rm N}{}^{15}{\rm N}$ were recorded at high resolution with a vacuum-ultraviolet Fourier-Transform spectrometer fed by synchrotron radiation in the range 81 to 100 nm. The combination of high column density ($3\times 10^{17}$ cm$^{-2}$) and low temperature (98 K) allowed for the recording of weak spin-forbidden absorption bands exciting levels of triplet character. The triplet states borrow intensity from ${}^1Π_u$ states of Rydberg and valence character while causing their predissociation. New predissociation linewidths and molecular constants are obtained for the states $C\,{}^3Π_u(v=7,8,14,15,16,21)$, $G\,{}^3Π_u(v=0,1,4)$, and $F\,{}^3Π_u(v=0)$. The positions and widths of these levels are shown to be well-predicted by a coupled-Schroedinger equation model with empirical parameters based on experimental data on ${}^{14}{\rm N}_2$ and ${}^{15}{\rm N}_2$ triplet levels.

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A. N. Heays, B. R. Lewis, N. de Oliveira, W. Ubachs. 2019-11-18. The spin-forbidden vacuum-ultraviolet absorption spectrum of 14N15N. https://doi.org/10.1063/1.5130206

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