|Acquisition Program: ||EMW-FY08-06 - Counter Improvised Explosive Devices Spiral 2|
| ||RESTRICTION ON PERFORMANCE BY FOREIGN CITIZENS (i.e., those holding non-U.S. Passports): This topic is “ITAR Restricted”. The information and materials provided pursuant to or resulting from this topic are restricted under the International Traffic in Arms Regulations (ITAR), 22 CFR Parts 120 - 130, which control the export of defense-related material and services, including the export of sensitive technical data. Foreign Citizens may perform work under an award resulting from this topic only if they hold the “Permanent Resident Card”, or are designated as “Protected Individuals” as defined by 8 U.S.C. 1324b(a)(3). If a proposal for this topic contains participation by a foreign citizen who is not in one of the above two categories, the proposal will be rejected.|| Objective: ||The development of magnetic materials which exhibit scalable strong ferromagnetic precession properties with low damping factors for use in high-power microwave generation.
|| Description: ||Microwave oscillators based on ferromagnetic precession have been demonstrated for continuous-wave low-power devices. Traditionally, these devices use a small amount of ferromagnetic material with an externally applied bias in the oscillator feedback path. In this application, the ferromagnetic material is simply used as the resonator and operates at low power. It has been proposed to significantly increase the size and electrical length of the resonator and to pump it with a fast-rise pulse input to achieve high power microwave (HPM) generation. Significant material challenges exist that limit the efficiency of this method for HPM generation. In particular, magnetic precession damping reduces the efficiency and increases internal heating and reduces the maximum pulse repetition rate. Scalability is also another area that must be addressed. By nature, these materials exhibit strong nonlinear behavior that can be used to produce the desired oscillation. Optimized materials will allow for higher designed output powers for a given peak input field.
|| ||PHASE I: Based on desire to reduce magnetic precession damping, develop a meaningful measurement technique that will predict the performance of available ferromagnetic materials in high power microwave applications. Utilizing this new technique, measure the ferromagnetic precession properties of known/existing ferromagnetic materials in order to characterize their performance as well as derive the basis for a materials approach to enhance the desired properties.
|| ||PHASE II: Building off of the data and methods generated in Phase I, develop and validate new and novel ferromagnetic materials and fabrication processes of ferromagnetic materials that would result in improved HPM generation. Measure and validate performance gains through Phase I test methodology.
|| ||PHASE III: Address scale-up issues associated with manufacture of these new materials. Establish a pilot-scale manufacturing process in order to produce and verify consistent and predictable output. Transition technology for manufacturing for large scale.
PRIVATE SECTOR COMMERCIAL POTENTIAL/|| ||DUAL-USE APPLICATIONS: Improvements to these materials will have application to high-power energy transmission, specifically transformers, commercial electronics, radars, ocillators, delay lines, and power limiters.
|| References: ||
(1) Handbook of Magnetism and Advanced Magnetic Materials
(2) Handbook of Magnetic Materials, Vol. 18|
|Keywords: ||ferromagnetic, precession, microwave, oscillators, materials, IED|