Portal de Periódicos da CAPES

Laser-induced fluorescence spectra of Ba + * -He exciplexes produced in cold He gas

2004; American Physical Society; Volume: 69; Issue: 4 Linguagem: Inglês

10.1103/physreva.69.042505

1538-4446

Yoshimitsu Fukuyama, Yoshiki Moriwaki, Yukari Matsuo,

Atomic and Subatomic Physics Research

We report the observation of laser-induced fluorescence spectra of ${\text{Ba}}^{+*}\text{\ensuremath{-}}\text{He}$ exciplexes. The experiment is carried out in an environment of cold gaseous helium at a temperature range of $3--30\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. We have observed the emission spectra of exciplexes by means of excitation of the $6p\phantom{\rule{0.3em}{0ex}}^{2}P_{3∕2}\ensuremath{\leftarrow}6s\phantom{\rule{0.3em}{0ex}}^{2}S_{1∕2}$ transition of ${\text{Ba}}^{+}$ ions. It is found that these spectra are redshifted from the $D2$ emission line in the free space and are composed of several peaks. The experimental results are reproduced well by theoretical calculation of the emission spectra for vibrational levels of ${\text{Ba}}^{+*}\text{\ensuremath{-}}\text{He}$. We also investigate the vibrational dynamics of the $6p\phantom{\rule{0.3em}{0ex}}^{2}\ensuremath{\Pi}_{3∕2}$ state of ${\text{Ba}}^{+*}\text{\ensuremath{-}}\text{He}$, and we have determined the collision-induced vibrational relaxation cross sections of the $6p\phantom{\rule{0.3em}{0ex}}^{2}\ensuremath{\Pi}_{3∕2}$ state to be $9.7\ifmmode\pm\else\textpm\fi{}1.1\phantom{\rule{0.3em}{0ex}}{\mathrm{\AA{}}}^{2}$ at $15\phantom{\rule{0.3em}{0ex}}\mathrm{K}$.