Innovative Materials for Microwave Tube Applications

Atomic Layer Deposition (ALD) offers a powerful technique for changing the surface properties of a material while maintaining the bulk properties. This allows one to create a new class of materials where one combines excellent bulk properties of lower cost materials, such as copper, with desirable surface properties of rare or expensive materials, such as tungsten, platinum, titanium, molybdenum, or silver. It also provides techniques for dramatically reducing corrosion and erosion. ALD provides unprecedented control of surface coatings on a broad range of substrates, including metals and ceramics. One can create nanometer thick coatings sufficiently thin to retain the properties of the substrate, such as electrical and thermal conductivity, dielectric properties, and cost. This program will investigate applications for ALD in microwave and millimeter wave RF sources. Promising applications have already been identified and will be further developed. The Phase I program will investigate applications related to RF and electrical breakdown, RF loss, multipactor, metallization, work function reduction, and surface finish. If funded, the Phase I option will apply the technology coat internal microwave source structures for corrosion prevention. The Phase II program will test promising coating applications and develop ALD hardware compatible with RF source production.