Air Force Research Laboratory: Directed Energy Materials Program – High Power Microwave Windows Second Category Window

The US Air Force is in pursuit of materials technology advances for directed energy systems for high energy laser (HEL) systems, high power microwave (HPM) systems and mid-infrared laser source and laser development.

Materials advances for high energy lasers in the kilowatt range including new fiber laser materials, advances in current fiber laser materials and development of materials for high power optical isolation in fiber lasers is desired.

High power microwave systems require improvements in window materials to address window technology development for HPM systems. Particularly, pursuit of optical diamond for improved strength and toughness with lower cost production capability is desired. Additionally, for other HPM applications, improvements in window durability and optical transmission are desired to yield decreased absorption and reflection loss for the transmission of 300 megawatts of microwave power.

Multiple contract awards are anticipated with various dollar values. Contract periods of performance are anticipated to be for 36 months plus 3 months for final reports. The Directed Energy Materials Program is being initiated via release of this BAA Number 09-11-PKM announcement. This announcement describes the overall program. Calls to the BAA/solicitation will be issued to request cost and technical proposals for specific Directed Energy Materials technologies in one or more of the following technical areas: High Energy Laser Materials, including High Energy Laser Fibers Development and Improvement and Optical Isolation, Mid-Infrared Laser Source and Laser Development, and High Power Microwave Windows. BAA Calls will contain descriptions of the Directed Energy Materials efforts to be addressed, anticipated period of performance, and the expected dollar range for requested proposals. Once a BAA Call is issued on the Federal Business Opportunities (FedBizOpps) website, offerors will have 30 to 45 calendar days (the actual period will be specified in the BAA Call(s)) from the announcement date to submit cost and technical proposals. Proposals received outside of the set forth period (i.e. a BAA Call already issued and the proposal due date has passed, or a BAA Call has not yet been issued) will not be reviewed and will be returned to the offeror. NOTE: Proposal receipt after the due date and time shall be governed by the provisions of FAR 52.215-1(c)(3). Multiple BAA Calls are anticipated and may be announced sequentially or concurrently. The Government also reserves the right to make no award against any subsequent BAA Call.

Address technical questions to: William Mitchell, 3005 Hobson Way, Wright-Patterson AFB, OH 45433, 937-255-9583, William.Mitchell@wpafb.af.mil.

CALL 5: High Power Microwave Windows Second Category Window
Systems utilizing the second category window operate with comparatively short, higher power (100s MW) pulses of a few hundred nanoseconds, and typically operate at frequencies close to 1 GHz. Catastrophic window failure caused by electric field-induced avalanche breakdown limits the maximum power capability of second category sources. Modeling of the window and mounting components, as well as transitions from the waveguide to eliminate potential multifactor-initiating conditions is an important aspect of the development. The design should also minimize the population in the window area of stray “seed” electrons originating from operation of the source itself. Window development tasks include, but are not limited to: 1) Optimization of the dielectric window material, nearby metallic components and any low emission coatings or other surface treatment to be employed. 2) Development of construction/assembly details, conditioning protocols and operating procedures that minimize extrinsic sources of field emission and avoid recontamination of window and nearby surfaces. Window strength should be great enough to withstand a three-atmosphere pressure differential. Future platforms for these systems will also require the weight and volume of all components, including the output windows, to be minimized to the greatest practical extent. This task area program is comprised of tasks requiring a total of three years of technical effort.