A quick measurement system of a continuous absorption spectrum was constructed and applied in ion beam pulse radiolysis.

Transient absorption spectra during and after pulsed ion beam irradiation could be obtained within a few minutes.

High sensitivity of 0.001–0.003 in absorbance was attained in the range from 260 to 660 nm.

Transient species, (SCN)₂^•−${{\left(\mathrm{S}\mathrm{C}\mathrm{N}\right)}_2}^{•-}$, was observed in KSCN aqueous solution.

Transient species having different absorption bands, Br₂^•−${{\text{Br}}_2}^{•-}$ at 360 nm and Br₃⁻${{\text{Br}}_3}^{-}$ at 260 nm, were observed simultaneously in NaBr aqueous solutions.