High Current Cold Cathode Employing Diamond and Related Materials

Thermionic cathodes are in use in an overwhelming majority of vacuum electronics devices, including high-power RF sources used to drive particle accelerators. These cathodes do not operate reliably or have long lifetime if their current density exceeds 5-10 Amperes/cm2. Artificial diamond and related materials, produced by chemical vapor deposition, appear to be an attractive alternative, which could improve performance for high-power RF sources and electron-beam triggered active high-power phase shifters and switches. Artificial CVD diamond and related material cathodes are to be prepared with a range of morphologies for evaluation as high current density cathodes, and as current amplifiers. Low power tests are planned for Phase I, and high power tests for Phase II. Commercial applications and other benefits: Vacuum electronics devices for civilian and military use represent a billion-dollar world wide industry. The industry has long sought a reliable cold cathode to replace the commonly-used thermionic cathode. Success with this project could allow introduction of a new class of cathodes, with an incalculable market value