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9 Phase I Selections from the 98.1 Solicitation

(In Topic Number Order)
735 State Street., PO Drawer 719
Santa Barbara, CA 93102
(805) 963-8761
Scot R. Fries
DSWA 98-002
Title:High Repetition Rate Microwave Modulation
Abstract:Several important emerging applications require efficient, high-speed high-duty-cycle, amplitude modulation of high levels of microwave power, with low cost and small size-and-weight. The modulation frequency and average power required for these applications are far beyond the capabilities of existing technology. MRC proposes to research and develop two alternative methods of achieving square-wave modulation at rates as high as MHz and beyond. One proposed method uses innovative variations of RF pulse-compression techniques demonstrated by the linear accelerator community to achieve such modulation at efficiencies in the vicinity of 90%. This approach uses a CW microwave source and RF cavities to chop up, delay, and stack pulses, resulting in peak output power much higher than that of the source (e.g., about triple for 33% duty cycle operation). The other approach, aimed primarily at extremely-efficient crossed-field microwave devices (CFDs), achieves modulation efficiencies above 96% using relatively low-cost pulsed-power components, by essentially reducing the problem to modulation of the tube's dynamic impedance alone. MRC will be assisted in this endeavor by Litton Systems, Inc., which is sufficiently interested in the potential of this project to provide support during Phase I free of charge. In addition to the requirement for this technology in the DoD HPM community, there is substantial need for highly -efficient, low-cost, high-speed AM modulation of high microwave power in applications such as radar, especially airborne radar. AM modulation currently involves more expensive modulators or very inefficient linear microwave amplifiers that draw considerable power during the off cycle.

2235 Polvorosa Avenue, Suite 230
San Leandro, CA 94577
(510) 483-4156
Mehadevan Krishnan
DSWA 98-003
Title:Ultrafast Gas Curtain and Wire-Reinforced X-Ray Window Debris Shields
Abstract:Alameda Applied Sciences Corporation (AASC) proposes to develop two components of a three-component, survivable debris shield for large area test exposures to cold (1-5keV) x-rays. These elements also have commercial potential in accelerators and in radiography. The elements are: an ultrafast gas curtain designed to be located close to the x-ray source to deflect plasma debris as well as ~um sized debris particles so that they miss the test object located at >15 cm from the source; a 1-D or 2-D grid that supports a thin soft x-ray window, making it far more robust than a free-standing foil, with high open area (~90%) and negligible artifacts in the test plane due to the grid structure. The role of this robust transmissive membrane is to stop those particles that have not been deflected by the gas curtain. These two elements are combined with an electromagnetic shutter, whose role is to stop larger but slower moving particles and late time hot gases. The three-pronged defense proposed by AASC, the gas curtain, electromagnetic shutter and robust transmissive x-ray window, constitute a debris mitigation system that is useful for today's simulators, while being eminently scaleable to the larger fluence-area products required by tomorrow's simulators. When z-pinch or laser produced plasmas are used as point x-ray or XUV sources for sub-micron lithography and microscopy, the mask/wafer region must be shielded from particulate debris. The debris shields developed here might be suitable for this purpose. Accelerator beamlines might also use these shields to protect delicate components from debris due to failures in vacuum beamlines or to make vacuum windows more robust.

8A Gill Street
Woburn, MA 01801
(617) 935-2030
Peter Norris
DSWA 98-005
Title:A Novel III-Nitride UV Avalanche Photodetector
Abstract:NZ Applied Technologies proposes to develop gallium nitride and aluminum gallium nitride high sensitivity avalanche photodetectors for solar blind ultraviolet wavelength applications. Solar blind ultraviolet avalanche photodetectors and position sensitive arrays with high sensitivity have broad applications in military, space, automotive, engine monitoring, flame detection, and environmental monitoring. The Al(x)Ga(1-x)N direct wide bandgaps covers from 3.4 to 6.2eV corresponding to a wavelength range of 365 to 200nm. These are ideal materials for developing UV photodetectors due to relatively high mobility, sharp cut-off wavelength, and high quantum efficiency. In Phase I, we will demonstrate the feasibility of the GaN/AlGaN APD solar blind photodetectors through the use of modeling and iterative fabrication runs. To overcome the high dislocation density problem found in traditional III-nitride MOCVD growth methods, we will use a novel approach to device structures coupled with the proven MOCVD technique. Using this novel APD structure we can effectively reduce dislocation density and fabricate the homojunctions and heterostructures, which are ultimately required by the APD device. In Phase II, we will refine the device designs, improve device performance, and to bring this high sensitivity ultraviolet detector to the marketplace. There are numerous commercial applications required for high sensitivity ultraviolet solar blind photodetectors such as automotive, engine and environmental monitoring, and flame detection.

119 Technology Drive
Bethlehem, PA 18015
(610) 861-6930
Scott Massie
DSWA 98-005
Title:Enhanced Reliability of Radiation-hardened III-V Semiconductor-based Field Effect Transistors Using C-doped Low-temperature Buffer
Abstract:Low-temperature MBE grown GaAs (LT-GaAs) contains a high concentration of excess As which gives rise to ultra-fast carrier-trapping time and excellent radiation hardness. In as-grown layers most of this excess As is in the form of As(Ga) antisite defects, of which only ~1% are ionized. Thermal annealing upon overgrowth with a device structure or during device processing results in a decrease of the As(Ga) concentration by about a factor of 100, accompanied by out-diffusion of excess As into adjacent layers. The benefits of LT-GaAs buffer layers for device isolation and increased radiation hardness can thus be realized only if their stability can be improved. Doping the LT-GaAs layers with Be (LT-GaAs:Be) can thermally-stabilize As(Ga) antisite defects and increases their incorporation. However, Be is known to be a relatively mobile element at high temperatures and LT-GaAs:Be may suffer from undesirable concentration-dependent diffusion at high doping levels. Here, we propose the use of C as an alternative p-type dopant in LT-GaAs. The combination of larger lattice concentration and superior thermal stability should make LT:GaAs:C a promising technology for radiation-hard field effect transistor (FET) applications. The proposed technology will offer enhancement in radiation hardness, thermal stability and reliability of III-V semiconductor-based field effect transistors compared to conventional undoped and Be-doped low-temperature buffers.

901 Pennsylvania,NE
Albuquerque, NM 87110
(505) 268-3379
Walter R. Keller
DSWA 98-006
Title:Hardness Validation by Verified Analysis (HV2A) Methodology for Advanced Materials
Abstract:Ktech proposes to develop a HV2A methodology for the assessment of nuclear weapon effects on new materials that are candidates for inclusion in strategic and tactical military systems. The methodology (1) provides an estimate of the system requirements and operation environments for each application specific material/structure, (2) establishes the critical response modes, (3) provides a framework for the development of detailed physical models for the critical response, (4) establishes the procedures to verify and validation of the response model, (5) identifies the required material property tests and the necessary validation tests, (6) selects the AGT environments and techniques for the material property and validation experiments, and (7) a vulnerability statement for the material for the specific application. The use of the Damage-Response Mode Matrix (DRM) to define the critical response modes minimizes the model development, material characterization and validation necessary to develop a confident vulnerability statement for a new material in a specific application. The methodology will be used to develop a program plan for the evaluation of two sets of new application specific structures/materials in a Phase II program. Full utilization of recent advances in computing technology, x-ray simulator development and simulator diagnostics will be made in the development and implementation of the methodology. The methodology provides for the generation of the data (analysis and test) necessary to evaluate the vulnerability of a material/structure introduced into a strategic and tactical military system as a result of maintenance and life cycle procedures. Such issues will become increasingly important as we continue to maintain the preparedness of our aging stockpile. In industry, the same methodology can optimize welding, lithography, etching and material processing techniques.

PO Box 644
Unionville, PA 19375
(610) 444-2383
Kelly Reuter
DSWA 98-008
Title:Flexible EMP Shielding Material
Abstract:During the Phase I, a lightweight, multilayer coating will be deposited onto copper wire and the wire woven into a mesh. The coating provides a high level of EM shielding, including magnetic shielding, EMP shielding and powers line filtering. The woven mesh will form a flexible shield with similar properties. Draped over existing equipment or used to line the walls, it will provide temporary and reusable EMP protection. Unlike conventional magnetic shielding approaches, which rely on high permeability layers, this coating uses the interaction between a good conductor and the magnetic layer to produce the high absorption. This results in a low cost film with less sensitivity to handling and improved high field performance. Since the wire consists primarily of copper, it retains much of the ductility of copper and can be bent or flexed. Samples of the mesh will be fabricated and measured during the Phase I and the ability of the wire to withstand flexing will be verified. Both the low and high frequency of the braid will be modeled during the program. This mesh will have superior electromagnetic shielding properties and will be of special interest to the military in applications requiring high SE in high fields. Commercial applications will include shielding from hazardous electromagnetic radiation (homes, schools) and sensitive equipment.

PO Box 2490, 27520 Hawthorne Blvd., Suite 263
Rolling Hills Es, CA 90274
(310) 541-2227
Herman J. Carpenter
DSWA 98-013
Title:Efficient Digitization of Nuclear Fireball Film
Abstract:The objectives of the proposed work are to develop the technical feasibility and detailed requirements for new methods and technology to decrease, substantially, the cost and time required to digitize and store high-speed, high-resolution film without sacrificing the spatial and grayscale depth of the original film. The work will be aimed at improvements that would make it practical to digitize and archive the entire U.S. nuclear fireball technical film database. Successful Phase I and Phase II efforts would culminate in the implementation of the developed technology into the DSWA DARE Data Engineering process. The results of this research could be of great value to the commercial film digitization and processing industry, in support of entertainment motion pictures, advertising, data archiving, and other film applications.

7585 East Redfield
Scottsdale, AZ 85260
(602) 607-4838
Robert Putnam
DSWA 98-016
Title:LPI Digital Wireless Video and Data Modem Video for Critical Asset Security
Abstract:In the proposed SBIR Phase I program, SiCOM will: 1) demonstrate and parametrically field-characterize BitSURE(tm) an innovative and unprecedented interference and multipath tolerant spread-spectrum wireless high speed digital communications technology; and 2) develop a point modem design for a revolutionary reduction in size, power and cost for Phase II using SiCOM's(tm) unique Application Programmable Integrated circuit (APIC(tm)) design and fabrication resources. BitSURE(tm) modem technology creates a robust communication link under a wide rang of conditions, including high interference, distortion, and jamming. BitSURE's(tm) flexible spreading capability accommodates all link conditions and provides protection against unauthorized detection through lower spectral density and the intentional use of local interference. Thus, BitSURE(tm) is ideal for a variety of high-speed wireless communications applications where link pathologies make traditional communications impractical, or where such pathologies are part of a strategy to mask the communications link. BitSURE(tm) technology provides for error rate of 10(-10) or better, facilitating encryption and reliable transmission of critical data as well as high resolution live video. The proposed program, through Phase II, will dramatically extend design and functionality, and provide an entry into Phase III, where BitSURE(tm) modems will be developed as commercial and military products. Anticipated products resulting from a successful program will benefit a wide variety of military and commercial applications. Military applications include covert high-speed communications, tactical communications and DARPA's GLOMO program. Commercially, SiCOM will sell ICs for modems for unlicensed bands, where interference is rapidly becoming a serious problem, for uses such as: bypass of wired infrastructure, wireless T1 links to businesses, schools, internet service providers, etc., and campus building/LAN bridges.

24 Thorndike Street
Cambridge, MA 02141
(617) 661-0700
N. Albert Moussa
DSWA 98-023
Title:A Near-Source Model for Chemically Reacting Radionuclides
Abstract:We propose to develop a near-source model for the release of chemically reacting radionuclides. The model structure is based on an available code for reacting chemicals. The model will include interactive effects of nuclear transformation, chemical reaction, and plume physical motion. Such a model will provide fast and accurate predictions for the source characterization and transport of radionuclides in the near-source field and bridge the gap between source modeling and large-scale meterological predictions. It will be interfaced with existing HPAC capability to strengthen its applicability and predictability in providing real-time information for radiological emergencies. The code, complete with a graphical user interface, will run on computers equivalent to a Pentium PC. The code can be used in assisting government agencies such as DoD, DoE, NASA, EPA, and their contractors in assessing potential collateral effects of nuclear hazard from facilities and weapons. The code can also be applied by both government agencies and private industries for environmental assessment of accidentally released hazardous materials.