High-speed imaging captures blast initiation

The development of new detonation systems requires diagnostic imaging techniques capable of accurately characterizing detonator functionality. Using a SIM-8 ultrahigh-speed framing camera, Specialised Imaging (Tring, UK; www.specialised-imaging.com) has demonstrated such a system.

Applied to short-duration electrical-pulse detonators such as the exploding bridge wire and exploding foil initiator, the technique allows initiation of secondary explosives to be done with a higher level of safety, repeatability, and reliability than is achievable with hot wire detonators.

A spark source was placed behind the event to produce a pseudo-schlieren imaging system able to see through the bright flash produced by an exploding blast initiator that normally obscures the ejection of the disc and fragments. Framing data (50-ns exposures, 250-ns separation) is presented that clearly shows the shock waves from the blast as well as the ejected fragments.