Luminescence induced in liquids and gases by alpha particle excitation

Abstract

The action of ionizing radiations on water and aqueous solutions has been the subject of investigation for many years. In that time a considerable amount of quantitative evidence has been accumulated, but agreement between different authors is limited. The chemical effects produced by radiation are fairly well known, but the physical action which produces the reactive species is not very well understood. Theoretical work is based mainly on results obtained in the gas phase and the extrapolation to the condensed state is not necessarily valid. The following brief survey covers the most generally accepted evidence and the theories which have been developed from it.Because ionization is the most conspicuous feature of the radiations involved, emphasis has been directed on the ions as the source of the chemical action, although, depending on the system, only about half the energy of the radiation is used in their production. The possible role of excitation, although recognized, has received much less attention.