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Development of Methods and concepts for Reducing Munitions Vulnerability to EMI and EMPe Batteries for Munitions and Weapon Platform

Description:

TECHNOLOGY AREA(S): Weapons 

OBJECTIVE: Develop and demonstrate innovative methods for determining vulnerability of munitions components and integrated munitions to electromagnetic interference (EMI) and pulse (EMP) and innovative and feasible packaging concepts for significantly reducing these vulnerabilities. 

DESCRIPTION: Exposure of munitions and its components to high levels of electromagnetic interference (EMI) and electromagnetic pulse (EMP) is one of the threats that can result in catastrophic consequences. The increasingly pervasive use of electronics of all forms represents the greatest source of vulnerability to EMI and EMP. Shielding of electrical and electronic devices and systems from catastrophic effects of high levels of EMI and EMP radiation presents an ongoing challenge. This problem is exacerbated by the wide range of EMP devices ranging from hand-held, operating from battery packs to much larger systems capable of rendering havoc over many city blocks. Additionally, the broad emission frequency spectrum makes a single technology solution unattainable. Currently used EMI and EMP shields are effective for the protection of electrical components under small levels of such electromagnetic illumination. In theory, ferro-magnetic cages can provide adequate protection but are mostly impractical for most munitions applications due to the volume constraints and the need for sensory and other device exposure to outside world. We are seeking innovative solutions, which represent revolutionary departure from current thinking of the day. Today, shield technologies are concerned with minimizing the electromagnetic radiation coupling through access ports or wires connecting to the outside. Under certain simplifications, closed form theoretical solutions are aiding in understanding the effectiveness of these structures. Realistic solutions are tractable using finite integration techniques (FIT), method of moments (MoM) and finite-difference time-domain (FDTD). Such solutions may also be extensible to wearable EMI and EMP shields for protection of military personnel and weapon platforms. Responsive proposals will describe novel approaches to minimizing damage to strong EMI and EMP exposure. Some of these techniques will include the use of meta-materials, composite material with nano-structures that minimize transmission through a combination of scattering, guiding and absorption. A clear path to validation, which does not require a strong EMI and EMP sources, is expected. Additionally, the efficacy of the structures needs verification through numerical solvers, based on physical models for EM propagation and interaction. Use of anechoic chambers for experimental characterization is encouraged. The developed technologies must add minimal volume to existing component. Proposers should approach the problem of vulnerability to EMI and EMP from a perspective of levels of protection of assets. Such assets could be on a system level or on a component level. As we can expect even the best metallic enclosure may not necessarily protect the internal electronic contents of a system, and the idea of a faraday cage needs to be looked at carefully. Generally one can look at the problem of EMP testing on a local area network and the coupling of electromagnetic energy on 200 feet of Ethernet line. During actual testing on a 25-foot of Ethernet line, the transient currents indicate that the electronics could be expected to see roughly 100 amperes to 700 amperes of current transients on typical Ethernet cables. Proposals must address levels of protection from various conventional sources. A very good literature search of reviewed literature is needed. As the program advanced to phase II and phase III, information about levels of protection and methodologies that result from the phase I effort will likely become sensitive information. 

PHASE I: Develop innovative packaging concepts to protects electrical and electronic components as well as other sensitive components of munitions from high electromagnetic interference (EMI) and pulse (EMP) radiation. Develop innovative methods for determining vulnerability of munitions components and systems to high electromagnetic interference (EMI) and pulse (EMP) using computer modeling and simulation methods, to be followed by validation testing in laboratory environment. 

PHASE II: Using the developed novel modeling and simulation capabilities and methods to validate the results in laboratory tests, design and fabricate prototypes of selected critical components used in munitions, particularly those with input and/or output wiring, with each of the selected packaging concepts. Demonstrate the effectiveness of the developed concepts in laboratory tests in anechoic chamber and provide prototypes for tests subjecting them to high levels of EMI and EMP. 

PHASE III: The development of methods and low cost and low volume means of significantly reducing vulnerability of electrical and electronic and other sensitive devices and equipment to high levels of electromagnetic radiation, particularly in the form of high level EMI and EMP is one of the challenges of today’s computer controlled and highly automated society. Such vulnerabilities can have catastrophic consequences in many critical civilian as well as military related areas. As such, the development of novel methods to model and simulate such component and system vulnerabilities to be followed by reliable validation via scaled down laboratory testing will therefore have a wide range of civilian as well as military applications. 

REFERENCES: 

1: High Power Microwaves, J. Benford, J. Swegle, E. Schamiloglu, Taylor & Francis, New York, 2007.

2:  Microwave Engineering, 3rd Ed., M. Pozar, John Wiley & Sons Inc., New Jersey, 2005.

3:  R. Pouladian-Kari, A. J. Shapland, T. M. Benson, "Development of ferrite line pulse sharpeners for repetitive high power applications," Microwaves, Antennas and Propagation, IEE Proceedings H, 1991, Vol. 138, pp. 504–512.

4:  Characterization of a Synchronous Wave Nonlinear Transmission Line, P. Coleman, et al., Proc. Pulsed Power Conf., pp. 173-177, 2011.

KEYWORDS: Electromagnetic Interference; Electromagnetic Pulse; EMI; EMP; High Power Radio Frequency; High Power Microwave; Directed Energy 

CONTACT(S): 

Dr. Carlos Pereira 

(973) 724-1542 

carlos.m.pereira1.civ@mail.mil 

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