Use of an optical multichannel analyzer for recording absorption spectra of short-lived transients

Characteristics of an adapted commercial optical multichannel analyzer system for recording of transient absorption spectra in single-shot pulse radiolysis and flash photolysis are described. The features discussed include temporal (2 μs) and spectral (1 nm) resolution, signal-to-noise ratio and its improvement, linearity of response, and wavelength coverage (300–650 nm). The system is intermediate in both cost and capabilities compared to two other methods: (1) recording transient spectra by repetitive pulsing and (2) using an image converter streak camera. This system is convenient for discrimination of small differences in fine structured absorption of spectra short-lived species.