Some characteristics of the dissociation of $SF_6$ molecules in a strong infrared $CO_2$ laser field

An investigation was made of the role of secondary chemical processes in dissociation of $SF_6$ in a strong infrared field. It was shown that the dissociation yield in the absence of an acceptor decreased with the pulse number, this decrease being greater at higher initial $SF_6$ pressures. It was found that the primary dissociation yield, at least at energy densities $\Phi\geqslant3,5$ J/cm${}^2$ and $0,06\leqslant p_{SF_6}\leqslant1$ mm$Hg$, did not depend on pressure. When the molecules were excited near the dissocation limit (25-35 quanta/ molecule), the primary dissociation yield was in good agreement with the number of absorbed quanta found using a simple thermal model allowing for absorption by $SF_5$ molecules. An investigation was made of the role of an acceptor $(H_2)$ in the dissociation process and the time for transfer of vibrational energy from excited $SF_6$ molecules to hydrogen was estimated. The dissociation quantum efficiency of $SF_6$ was measured. It was concluded that when the $\nu_3$ vibration mode of the $SF_6$ molecule is excited, regardless of the excitation frequency, the vibrational distribution function is uniquely governed by the average energy absorbed by the molecules interacting with the field.