| Citation | Professor David Smith has carried out most successful and comprehensive studies of a variety of gas phase ionic reaction processes at thermal energies, including ion-molecule interactions, ion-ion and ion-electron recombination and electron attachment. In variety, depth and range of application this effort probably surpasses any other in the world. To achieve this he conceived, developed and exploited two unique apparatuses, the selected ion flow tube (SIFT) and the flowing afterglow Langmuir probe (FALP). The SIFT technique has now been adopted by many leading research groups around the world. His work has very wide application as is illustrated by the important contributions which he has made to aeronomy, astrophysics and astrochemistry, laser physics, plasma physics and plasma chemistry and also to the fundamental understanding of ionic reactions in the gas phase. As a result of his work, the direction of research in some established areas of these subjects has been greatly influenced and new lines of research have been initiated. |