3M™ Controlled Porosity Reservoir Cathodes are used in a number of specialized vacuum tube applications. They provide a long-lasting and uniform supply of barium to the cathode surface, and the amount of barium supplied can easily be controlled by altering the cathode’s design parameters.
Ideal for Vacuum Tubes
Used in a number of specialized vacuum tube applications, 3M™ Controlled Porosity Reservoir Cathodes (PDF, 313.97 Kb) consist of fine tungsten wires sintered in a compact structure with hexagonal patterns of pores. The resulting porous tungsten structure is brazed to a molybdenum cup that forms a cavity. This cavity is filled and sealed, and barium and oxygen diffuse from this reservoir through the tungsten material to reduce the work function of the cathode surface. This technology enables the production of smaller and dome-shaped cathodes, and is relatively insensitive to spacing between the cathode and focus electrode.
Precision Through Process
3M has over 60 years of industry experience manufacturing cathodes. Our highly controlled manufacturing processes are designed to ensure consistent product quality and to meet the exacting standards of a wide array of military and civilian applications. We control each stage of the cathode manufacturing process, from basic raw materials through the manufacturing of critical components to final assembly.
Learn more about 3M™ Cathodes and Electron Guns (PDF, 1.11 Mb)
Industries and Applications
- Long-range communications
- Printing technologies (lithography)
- X-ray equipment
- Scientific research (particle accelerators)
- Traveling wave tubes (TWTs)