Publications

AIP Conference Proceedings

Tappan, Alexander S.; Wixom, Ryan R.; Trott, Wayne T.; Long, Gregory L.; Knepper, Robert; Brundage, Aaron B.; Jones, David A.

Films of the high explosive PETN (pentaerythritol tetranitrate) up to 500-μm thick have been deposited through physical vapor deposition, with the intent of creating well-defined samples for shock-initiation studies. PETN films were characterized with microscopy, x-ray diffraction, and focused ion beam nanotomography. These high-density films were subjected to strong shocks in both the out-of-plane and in-plane orientations. Initiation behavior was monitored with high-speed framing and streak camera photography. Direct initiation with a donor explosive (either RDX with binder, or CL-20 with binder) was possible in both orientations, but with the addition of a thin aluminum buffer plate (in-plane configuration only), initiation proved to be difficult. Initiation was possible with an explosively-driven 0.13-mm thick Kapton flyer and direct observation of initiation behavior was examined using streak camera photography at different flyer velocities. Models of this configuration were created using the shock physics code CTH. © 2009 American Institute of Physics.

Tappan, Alexander S.; Long, Gregory L.; Welle, Eric W.; Renlund, Anita M.; McDonald, Joel P.; Jared, Bradley H.; Michael, Joseph R.

Abstract not provided.

Wixom, Ryan R.; Tappan, Alexander S.; Welle, Eric W.; Long, Gregory L.; Michael, Joseph R.; Brundage, Aaron B.

Abstract not provided.

Tappan, Alexander S.; Long, Gregory L.; Welle, Eric W.; Renlund, Anita M.; Michael, Joseph R.; McDonald, Joel P.; Jared, Bradley H.; Brundage, Aaron B.

Abstract not provided.

Proceedings of the 13th International Detonation Symposium, IDS 2006

Tappan, Alexander S.; Brundage, Aaron B.; Long, Gregory L.; Renlund, Anita M.; Kravitz, Stanley H.; Nogan, John J.; Wroblewski, Brian; Palmer, Jeremy A.; Baer, Melvin B.

A new approach to explosive sample preparation is described in which microelectronics-related processing techniques are utilized. Fused silica and alumina substrates were prepared utilizing laser machining. Films of PETN were deposited into channels within the substrates by physical vapor deposition. Four distinct explosive behaviors were observed with high-speed framing photography by driving the films with a donor explosive. Initiation at hot spots was directly observed, followed by either energy dissipation leading to failure, or growth to a detonation. Unsteady behavior in velocity and structure was observed as reactive waves failed due to decreasing channel width. Mesoscale simulations were performed to assist in experiment development and understanding. We have demonstrated the ability to pattern these films of explosives and preliminary mesoscale simulations of arrays of voids showed effects dependent on void size and that detonation would not develop with voids below a certain size. Future work involves experimentation on deposited films with regular patterned porosity to elucidate mesoscale explosive behavior.

Tappan, Alexander S.; Baer, Melvin B.; Brundage, Aaron B.; Long, Gregory L.; Renlund, Anita M.; Palmer, Jeremy A.; Baer, Melvin B.

Abstract not provided.

Long, Gregory L.; Renlund, Anita M.; Kravitz, Stanley H.; Tappan, Alexander S.

Abstract not provided.

Tappan, Alexander S.; Tappan, Alexander S.; Long, Gregory L.; Renlund, Anita M.; Kravitz, Stanley H.

Abstract not provided.