Characterization of the Radiation Environment Capabilities of Exploding Foil Initiators (EFIs)

InnoSys with the assistance of the University of Utah Nuclear Engineering Program (UU) proposes to develop a comprehensive and methodical approach to testing and characterizing the effects of X-ray, neutron, EMP, etc. on both the overall LEEFI/EFI and the various components (e.g. metals and dielectrics) that comprise the LEEFI/EFI. The ability of a low energy exploding foil initiator (LEEFI or EFI) to function in the SSP D5 missile system is to be investigated and demonstrated. Specifically, since the missile is subject to various strategic radiation environment environments; any electrical system must be robust enough to reliably operate during exposure to the elevated radiation environment. Many EFI designs exist in industry and their viability must be understood prior to use in systems which experience radiation environments. To provide potential users with a wider selection for their application and to promote new designs, characterization of the performance of bridge foils of varying materials and sizes will be conducted when subjected to various radiation environments, comprised of neutrons, gammas, X-rays, electrons, and Electromagnetic Pulse (EMP). The baseline application is for EFIs, which conform to MIL-STD-1316 and/or MIL-STD-1901, design and safety requirements for use in systems. Of particular interest is the effects of radiation on the narrowed bridge area (metal, e.g., aluminum, copper, gold, silver) and flyer (dielectric, e.g., polyimide, polyethylene terephthalate (PET)) aspects of the bridge foil such that the EFI would not fire or would prematurely fire. The Phase I deliverables would include an analysis-based “handbook” and recommended processes to evaluate typical common EFI bridge foil and flyer materials and how they react in various radiation environments for determining EFI viability in a system and/or narrow down design parameters for a custom EFI in a strategic system. Phase I Option would expand upon Phase I Base by conducting initial design specifications based on the Phase I Analysis-Based handbook and Phase I Final Report. The innovative approach we employ in our project is the coupling of experimental and simulations to provide predictive capabilities and to validate test results. Our proposed “optimal” integration of simulations and testing in the way of simulation leading testing and testing supporting simulation not only allows for validation, verification, and a predictive tool, but also enables true understanding of radiation interaction physics and, as a result, new design and material development. We will use a variety of radiation test facilities available at UU and LMTF, along with electrical testing facilities at InnoSys using different EFI materials/designs. It is worth noting that the combined capabilities of this team are also very unique and form an ideal platform for this proposed study to “enhance" the radiation capability of EFI through detailed study, understanding, and development.