Experiments on surface light-induced drift for various systems

✍ Scribed by G.J. van der Meer; B. Broers; R.W.M. Hoogeveen; L.J.F. Hermans

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 586 KB
• Volume: 182
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/0378-4371(92)90229-j

✦ Synopsis

Surface light-induced drift of a low-pressure gas results from velocity-selective optical excitation combined with state-dependent molecule-surface interaction. This effect has been studied for CH3F and OCS, rovibrationally excited by a CO: laser, interacting with various surfaces. For the R(4, 3) transition of 13CH3F, an increase in tangential momentum accommodation coefficient c~ upon excitation is found ranging from ~a = 1.0 × 10 3 for stainless steel to ~a = 14 × 10 3 for LiF(100) at 295 K. For this transition, the effect was also studied as a function of temperature for a quartz surface, resulting in a 40% decrease of ~a as the temperature is raised from 300 to 700 K. Experiments for the P(5) transition of OCS yield ~a = -0.53 x 10 -3 on a quartz surface at 295 K.