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Title: X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers

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 0.16 mm 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 0.53 mm 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. perpendicularmore » to the initiating current and electrical contacts. These results provide detailed flyer morphology during the operation of the EFI.« less

Authors:
; ; ; ; ; ;  [1]; ;  [2];  [3]
  1. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
  2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  3. National Security Technologies, LLC, Las Vegas, Nevada 89193 (United States)
Publication Date:
OSTI Identifier:
22596826
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 119; Journal Issue: 23; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALGORITHMS; ANISOTROPY; BRIDGES; CAMERAS; CHEMICAL EXPLOSIVES; COMPUTERIZED TOMOGRAPHY; DETONATORS; ELECTRIC CONTACTS; EXPLOSIONS; FOILS; IMAGES; METALS; MORPHOLOGY; PLASTICITY; PULSES; SUBSTRATES; SURFACES; THREE-DIMENSIONAL CALCULATIONS; X RADIATION

Citation Formats

Willey, T. M., E-mail: willey1@llnl.gov, Champley, K., E-mail: champley1@llnl.gov, Hodgin, R., Lauderbach, L., Bagge-Hansen, M., May, C., Buuren, T. van, Sanchez, N., Jensen, B. J., and Iverson, A.. X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers. United States: N. p., 2016. Web. doi:10.1063/1.4953681.
Willey, T. M., E-mail: willey1@llnl.gov, Champley, K., E-mail: champley1@llnl.gov, Hodgin, R., Lauderbach, L., Bagge-Hansen, M., May, C., Buuren, T. van, Sanchez, N., Jensen, B. J., & Iverson, A.. X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers. United States. doi:10.1063/1.4953681.
Willey, T. M., E-mail: willey1@llnl.gov, Champley, K., E-mail: champley1@llnl.gov, Hodgin, R., Lauderbach, L., Bagge-Hansen, M., May, C., Buuren, T. van, Sanchez, N., Jensen, B. J., and Iverson, A.. 2016. "X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers". United States. doi:10.1063/1.4953681.
@article{osti_22596826,
title = {X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers},
author = {Willey, T. M., E-mail: willey1@llnl.gov and Champley, K., E-mail: champley1@llnl.gov and Hodgin, R. and Lauderbach, L. and Bagge-Hansen, M. and May, C. and Buuren, T. van and Sanchez, N. and Jensen, B. J. and Iverson, A.},
abstractNote = {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 0.16 mm 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 0.53 mm 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.},
doi = {10.1063/1.4953681},
journal = {Journal of Applied Physics},
number = 23,
volume = 119,
place = {United States},
year = 2016,
month = 6
}
  • 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. The work described here 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,more » the 2 nd images the flyer about 0.16 mm above the surface but edges of the foil and/or flyer are still attached to the substrate. The 3 rd frame captures the flyer in flight, while the 4 th 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 0.53 mm 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.« less
  • Cited by 4
  • An investigation on the influence of Al/CuO reactive multilayer films (RMFs) additives on exploding foil initiator was performed in this paper. Cu film and Cu/Al/CuO RMFs were produced by using standard microsystem technology and RF magnetron sputtering technology, respectively. Scanning electron microscopy characterization revealed the distinct layer structure of the as-deposited Al/CuO RMFs. Differential scanning calorimetry was employed to ascertain the amount of heat released in the thermite reaction between Al films and CuO films, which was found to be 2024 J/g. Electrical explosion tests showed that 600 V was the most matching voltage for our set of apparatus. Themore » explosion process of two types of films was observed by high speed camera and revealed that compared with Cu film, an extra distinct combustion phenomenon was detected with large numbers of product particles fiercely ejected to a distance of about six millimeters for Cu/Al/CuO RMFs. By using the atomic emission spectroscopy double line technique, the reaction temperature was determined to be about 6000-7000 K and 8000-9000 K for Cu film and Cu/Al/CuO RMFs, respectively. The piezoelectricity of polyvinylidene fluoride film was employed to measure the average velocity of the slapper accelerated by the explosion of the films. The average velocities of the slappers were calculated to be 381 m/s and 326 m/s for Cu film and Cu/Al/CuO RMFs, respectively, and some probable reasons were discussed with a few suggestions put forward for further work.« less