Ultrafast pulse radiolysis

Femtosecond time-resolved pulse radiolysis was developed using a femtosecond electron bunch and a femtosecond laser light. This development initiated the experimental study of pulse radiolysis in the femtosecond time region. The femtosecond transient absorption kinetics of hydrated electrons in water radiolysis was observed. The initial yield of the hydrated electron in water radiolysis was obtained to be G=4.6±0.3. The experimental data indicates that about 10% of the hydrated electrons undergo the spur reaction with H3O+ cations and OH radicals in the first 10 ps. The dependences of the transient absorption signal on the electron bunch length, the electron charge, and the sample thickness were also investigated.