A spur unfolding model for the radiolysis of water

A previous treatment of the theory of the chemical action of high energy electrons contains the spur yield, Gsub(sp), as a parameter. Use of this theory allows one to obtain Gsub(sp) for any reaction for which sufficient experimental data are available. A model for the spur in dilute aqueous solution is considered here with the aim to provide some reaction details in that track entity. From the detailed considerations presented here, it appears that the size of the spurs must be taken as decreasing with the number of radical pairs initially present, if the radiation chemical yields are to be compatible with experiments. There is an unavoidable lack of uniqueness in such treatments which has led to the question of further comparison with experiments. This important question is also discussed. (author)