The Discovery Xenon Flash (DXF) source module employs a High Speed Xenon-pulse Delivery source (HSXD) which has considerably higher efficiency, lower costs and less maintenance than equivalent systems. A reflective optic configuration of our design effectively harnesses the power of a Xenon flash tube and, with the aid of proprietary wave guides, delivers it to the specimen inside the Environmental Module. DXF 900 produces a pulse width of 400 μs to 600 μs and uniformly concentrates the power from the flash source directly on the entire face of the specimen. Due to this optimized optical arrangement and the broad light spectrum, specimens as large as 25 mm in diameter can be illuminated with sufficient energy to make a high-accuracy measurement. The use of large samples diminishes errors associated with inhomogeneity and permits representative measurements of poorly dispersed composites.