Interaction of slow electrons with high-pressure gases (quasi-liquids): synthesis of our knowledge on slow electron-molecule interactions. Progress report, February 1, 1981-January 31, 1982

A crucial step in our efforts to develop not only a coherent picture of radiation interaction with matter, but also to understand radiation effects and mechanisms, as well as the effects of chemical pollutants and toxic compounds, is to relate the often abundant knowledge on isolated molecules (low pressure gases) to that on liquids or solids. To understand the roles of the physical and chemical properties of molecules in biological reactions, we must know how these isolated-molecule properties change as molecules are embedded in gradually thicker and thicker (denser and denser) gaseous and, finally liquid environments. High pressure (40 to approx. 8000 kPa) electron swarm experiments are currently in operation yielding the first information as to the effects of the density and nature of the environment on fundamental electron-molecule interaction processes at densities intermediate to those corresponding to low pressure gases and liquids, and the gradual transition from isolated molecule to condensed phase behavior. Additionally, there is a pressing need for basic physical data on the electronic states of atmospheric halocarbons in general, and of polycyclic aromatic hydrocarbons in particular. Halocarbons are usually photochemically reactive and some of their fragments might attack the atmospheric ozone (O3). Finally, as part of the effort to extend the basic understanding of fundamental processes in radiation (ionizing and non-ionizing) interaction from simple to complex molecules, knowledge on slow electron-molecule interactions is synthesized. Progress is outlined