Diamond Amplified Photocathode at BNL

Diamond amplified photocathode

Developed at:

Brookhaven National Laboratory, New York
Developed in:
Result of NP research:
Electron cooling R&D for RHIC
Application currently being supported by:
Impact/benefit to spin-off field:

Highly efficient, hermetically sealed photocathode.

A new approach to generate high average, high-brightness electron beams from a laser photocathode RF gun is being developed at BNL�fffd;s Collider-Accelerator Department. The principle of this device is based on the generation of a large number of secondary electrons in diamond. The primary electrons are generated by a conventional photocathode and accelerated towards the diamond by a voltage of a few thousand volts.

The secondary electrons, which can be more numerous than the primary electrons by one to two orders of magnitude, drift through the high-quality synthetic diamond and exit on the other side. The emission into vacuum is made possible by hydrogenation of the diamond�fffd;s surface. The diamond amplified photocathode may improve the performance of laser-photocathode RF guns by providing a robust, high quantum-efficiency, low thermal-emittance cathode.

In the figure above Schematic diagram of a diamond amplified photocathode.