Excitation and ionization of Hg by metastable states of N2 and CO

Abstract

When metastable states of N2 and CO collide with mercury atoms, the excitation energy can be transferred to the mercury atom, yielding a fluorescence in the spectral lines of mercury. This note describes observations of this process using a thermal beam of metastable molecules excited by electron impact. Metastable CO excites only the 63P levels of Hg. Metastable N2 excites predominantly 63P, but some 10% of collisions excite 61P, and higher states are also excited. In addition, ionization of Hg by excited N2 (but not by CO) is reported. Other observations are reported briefly.