In-Line Pulsed Holography of Shock-Induced Ejecta

The problem of measuring ejecta particle size distribution is discussed. A portable holographic system developed by the authors for in-line pulsed holography is presented. The system can be used to record holograms with a field of view of ≈20 mm diameter with a depth of more than 20 mm and flows of lead particles with a size of ≥3–5 μm moving at velocities of up to ≈2 km/s. Shock-induced ejecta moving in vacuum and consisting of both individual particles 5–100 μm in size and predominantly filamentary structures 3–10 μm thick were recorded using the portable holographic system and are given in the paper. Methods of analog and digital recording and reconstruction of holograms and the problem of identifying particles in images reconstructed from recorded holograms are discussed.