Gated Field Emission Cathode RF Gun

High-brightness electron beams are required for a number of applications, from advanced accelerators to 4thgeneration light sources. However, the current technology for producing such beams requires an expensive, complicated laser system to drive a photocathode in an RF gun. This technology is difficult to extend to high duty cycles, as is necessary for many applications in research and industry. In this proposed project, RadiaBeam will develop a novel, gated field-emission electron source using carbon nanotubes (CNTs). While field-emission cathodes have been under investigation for use in RF guns for more than two decades and can produce relatively low emittance for a given cathode size, they have typically either produced very low currents or are prone to damage and are unable to directly produce short pulses. This proposal addresses these issues with two innovations: the use of robust CNT films capable of producing good current density with low thermal emittance, and a novel RF gun design capable of gating the emission from the cathode to pulses of < 100 ps. Commercial Applications and Other Benefits: Besides applications in high-energy physics and next-generation light sources, the CNT cathode based gun described in this proposal could also be applied wherever thermionic cathodes are used in commercial applications, such as in medical radiotherapy linacs, cargo inspection linacs, and industrial irradiation systems. The gated CNT cathode gun would produce better beam quality, reduce the cost, and potentially increase the reliability of such systems