Level scheme of the Sn/Sn<sup>−</sup> system

2013-06-10T00:00:00Z (GMT) by M Vandevraye C Drag C Blondel
<p><strong>Figure 1.</strong> Level scheme of the Sn/Sn<sup>−</sup> system. <sup>e</sup><em>A</em> labels the ground-to-ground detachment transition that defines the electron affinity; 'measured' labels the transition measured in this study. The <sup>2</sup>D levels of Sn<sup>−</sup>, which do not play any role in this work, were observed by Scheer <em>et al</em> (<a href="http://iopscience.iop.org/0953-4075/46/12/125002/article#jpb466134bib20" target="_blank">1998</a>).</p> <p><strong>Abstract</strong></p> <p>A beam of Sn<sup>−</sup> ions produced by a caesium sputtering ion source is photodetached in the presence of an electric field, with a single-mode ring Ti:Sa laser. The laser wavelength, about 806 nm, is set just above the excitation threshold of the <sup>3</sup>P<sub>2</sub>, highest fine-structure sublevel of the <sup>3</sup>P ground-term of Sn I. The photoelectron energy is measured by photodetachment microscopy. The measured photodetachment threshold is 1239 711.8 (11) m<sup>−1</sup>, from which an improved value of the electron affinity of tin can be deduced: 896 944.7 (13) m<sup>−1</sup> or 1.112 070 (2) eV.</p>