An improved apparatus for performing vacuum uv flash photolysis-kinetic spectroscopy has been constructed. The deviceconsists of a compact coaxial arrangement of six capacitors and six electrode pairs symmetrically placed about a hexagonal reaction vessel of large aperture. The reaction vessel contains LiF windows to transmit far uv radiation. The six pairs of electrodes and six capacitors are connected separately and are synchronously fired, uniformly illuminating the reaction cell. The photolytic light pulse duration is about 5 microsec. More than 10(18) quanta enter the reaction vessel in the spectral region between 1050 A and 1600 A. The essential operating features of the apparatus are described.