Radiolysis of water vapor with fission fragments

Abstract

Water vapor, and mixtures of water vapor with radical and electron scavengers, have been irradiated with fission fragments a t temperatures from 170 to 365 "C and densities from 1-50 n~g / n~l .The unimolecular hydrogen yield is the same as in y-ray irradiations. In D20-C6HIz mixtures the HD yield and HD/H2 ratio are lower than in y-ray irradiations and N 2 0 and SF6 have little effect. The HD yield reaches a limiting value (G(HD) -4) with increasing linear energy transfer suggesting that a fraction of the D atoms formed are hot.

Multiple ionization in the earlier stages of water radiolysis

“…The application of this method has been limited so far to the case of low-LET radiations due to the lack of single and multiple ionization as well as electronic excitation cross sections (Inokuti 1988, IAEA 1988, which are necessary for the physical stage, and also to the lack of information about the dissociation of a multiply ionized water molecule making any simulation of the physicochemical stage very difficult. There are actually some studies for photons (Cairns et al 1971, Dixon 1970, Dutuit et al 1975, McKulloh 1976, Tan et al 1978 and electrons (Khare andMeath 1987, Scutten et al 1965) but the information is scarcer for ion impacts (Boyd andMiller 1969, ICRU 1996). The multiple ionization processes for photons generally result, however, from the electronic reorganization of the molecule, and we shall see that the result cannot be directly extrapolated to ions.…”

Chemical effects of fission recoils. II. Influence of density and oxygen concentration on product formation in ethylene

“…C4H7 + C2H5 -C6H12 (11) where C4H7 is the 1-butenyl radical. The rate constant for vinyl radical addition to ethylene (reaction 10) has not been reported but it is expected to be large.…”

Kinetic Isotope Effect for the Reaction of a Hydrogen Atom with Cyclohexane‐h12, Cyclohexane‐d12 and Cyclohexane‐1, 1, 2, 2, 3, 3‐d6 as Studied by the Radiolysis of Water Vapor‐Cyclohexane Mixtures

“…If D atoms were produced by Reaction (15), they should react with added c-C6D,, to give D2. because the deuterium atom cannot react with H 2 0 to give H D owing to the high activation energy required for Reaction (16),…”

“…1). However, it is difficult to describe a complete reaction sequence, especially including secondary reactions for the radiolysis of pure water vapor [9,10,15].…”