ON SELF-LIMITATION OF UV PHOTOLYSIS IN RARE-GAS SOLIDS AND SOME OF ITS CONSEQUENCES FOR MATRIX STUDIES

UV photolysis of small molecules embedded in rare-gas matrices is exam ined. We demonstrate that photolysis can be self-limited when products absorb the photolysing radiation. As a result of the rising absorptio n, in-situ detected luminescence of the photolysis product saturates f aster than its concentration. In particular, the present study support s the conclusion that 193 nm photolysis of hydrogen-containing species in Xe matrices produces hydrogen atoms in amounts comparable with the other dissociating part of the precursor. Also, we show that 193 nm r adiation activates mobility of hydrogen atoms in annealing, accelerati ng photochemical processes related to hydrogen mobility. (C) 1998 Else vier Science B.V. All rights reserved.