Radiolysisproduced

Radiolysis-produced species are chemical species formed as a direct or indirect consequence of radiolysis, the chemical decomposition caused by ionizing radiation such as X-rays, gamma rays, or energetic particles. The formation involves initial bond cleavage creating reactive intermediates such as radicals and ions, followed by a network of reactions that yield stable molecules. These products can be transient intermediates or long-lived species, depending on the medium, temperature, dose rate, and presence of scavengers or solutes.

In aqueous systems, water radiolysis is the most extensively studied case. Primary products include hydrated electrons (e_aq^-), hydroxyl radicals (•OH), and hydrogen atoms (H•). The yields of these species are described by G-values, which quantify moles produced per 100 eV of absorbed energy. Typical G-values in pure water at room temperature are approximately •OH ~ 2.7, e_aq^- ~ 2.8, H• ~ 0.6, with secondary products such as molecular hydrogen (H2) around 0.4 and hydrogen peroxide (H2O2) around 0.7. The subsequent chemistry leads to additional radiolysis-produced molecules, including oxidants, reductants, and various organic or inorganic products, depending on dissolved gases and solutes.

Outside water, radiolysis produces solvent-specific radicals, ions, and molecular products. In organic solvents, for example, solvated electrons and various radical species form with distributions that depend on solvent polarity and structure. The overall outcome is system-dependent, with radiolysis-produced species driving corrosion, material degradation, radiolytic sterilization, and radiochemistry applications.

Understanding radiolysis-produced species relies on kinetic modeling, scavenger studies, and spectroscopic measurements to map yields and reaction pathways under different conditions.