The main aim of this project is to demonstrate the potential of diamond components to improve the performance and reduce the cost of microwave and IR optical systems. The components addressed are insulators and windows for microwave travelling wave tubes, gyrotrons and klystrons, and windows for high power CO2 lasers. Diamond will be used to replace the present components fabricated from BeO, sapphire, ZnSe etc. The very high thermal conductivity and low thermal expansion coefficient of diamond will allow the systems to be run at higher powers with simpler cooling arrangements. The diamond deposition process will be optimised to give low microwave absorption, low permittivity, low IR absorption and scatter and high thermal conductivity material. This will be achieved by relating detailed measurements of the microwave, IR and thermal properties with the growth conditions and setting-up a feed back loop. Plasma modelling and diagnostics will be used to support the optimisation, and assist with the scaling-up of the deposition process to produce 100mm diameter self-supporting wafers. The electrical and mechanical properties of the diamond will be measured to allow demonstrator components to be designed. Detailed material characterisation of the diamond will be carried out to relate the measured properties to structural features and thus to the growth parameters. Techniques for cutting and polishing diamond will be developed to achieve the dimensions and surface finishes required for the demonstrator components. Brazing and other joining processes will investigated for attaching the diamond to metal mounts. Microwave tube and CO2 laser demonstrator components will be designed for use within demonstrations at two end user establishments. In one, the performance of a large diamond window will be assessed on a high power gyrotron, while on the other a diamond window will be used in a CO2 laser for cutting trials. Significant performance improvements over existing components of Sapphire and ZnSe are anticipated. New and replacement optical components (that could be replaced with diamond) are valued at over 60-100M ECU in the fields of CO2 lasers and microwave power tubes alone by the year 2005, but the application of diamond optics will be much wider than these, encompassing ruggedised IR cameras for fire fighting, surveillance, security and automotive applications as well IR and radar systems in aerospace environments. The consortium of partners which have been brought together to achieve these goals include four industrial companies involved in 1) the development of diamond deposition equipment, 2) the production and processing of diamond components, 3) the manufacturing of high power microwave tubes and 4) the manufacture of CO2 laser systems. They are supported by a number of European academic and research organizations capable in assisting in the detailed characterisation of materials and systems. The main achievements of this programme will be processes to produce diamond microwave and LWIR windows up to 80mm in diameter and the joining technology necessary to incorporate them in vacuum tight assemblies for existing industrial applications.
Funding SchemeCSC - Cost-sharing contracts
13108 St.paul Les Durance
DD2 3EL Dundee
78148 Vélizy - Villacoublay