Abstract
This paper reports on the results about the SF6 + Ba (surface) reactions as a function of the vibrational excitation of the polyatomic molecule. A thermal, vibrationally excited by a tunable CO2 laser, SF6 beam is collided with a Ba surface target under high vacuum conditions. The total negative ion yield is measured as a function of the laser wavelength. Preliminary results show a strong vibrational enhancement of the beam-surface reactions indicating important laser-assisted negative ionization effects. The results are discussed in the light of several possible reaction mechanisms.