학술논문

X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers.
Document Type
Article
Source
Journal of Applied Physics. 6/21/2016, Vol. 119 Issue 23, p235901-1-235901-4. 4p. 1 Black and White Photograph, 1 Diagram, 1 Graph.
Subject
*DETONATORS
*IMAGING systems
*X-ray imaging
*COMPUTED tomography
*ANISOTROPY
*MOSELEY'S law
Language
ISSN
0021-8979
Abstract
Exploding foil initiators (EFIs), also known as slapper initiators or detonators, offer clear safety and timing advantages over other means of initiating detonation in high explosives. This work outlines a new capability for imaging and reconstructing three-dimensional images of operating EFIs. Flyer size and intended velocity were chosen based on parameters of the imaging system. The EFI metal plasma and plastic flyer traveling at 2.5 km/s were imaged with short ∼80 ps pulses spaced 153.4 ns apart. A four-camera system acquired 4 images from successive x-ray pulses from each shot. The first frame was prior to bridge burst, the 2nd images the flyer about 0.16mm above the surface but edges of the foil and/or flyer are still attached to the substrate. The 3rd frame captures the flyer in flight, while the 4th shows a completely detached flyer in a position that is typically beyond where slappers strike initiating explosives. Multiple acquisitions at different incident angles and advanced computed tomography reconstruction algorithms were used to produce a 3-dimensional image of the flyer at 0.16 and 0.53mm above the surface. Both the x-ray images and the 3D reconstruction show a strong anisotropy in the shape of the flyer and underlying foil parallel vs. perpendicular to the initiating current and electrical contacts. These results provide detailed flyer morphology during the operation of the EFI. [ABSTRACT FROM AUTHOR]