title: Electron beam emission from a diamond-amplifier cathode.
abstract: The diamond amplifier (DA) is a new device for generating high-current, high-brightness electron beams. Our transmission-mode tests show that, with single-crystal, high-purity diamonds, the peak current density is greater than 400  mA/mm², while its average density can be more than 100  mA/mm². The gain of the primary electrons easily exceeds 200, and is independent of their density within the practical range of DA applications. We observed the electron emission. The maximum emission gain measured was 40, and the bunch charge was 50  pC/0.5  mm². There was a 35% probability of the emission of an electron from the hydrogenated surface in our tests. We identified a mechanism of slow charging of the diamond due to thermal ionization of surface states that cancels the applied field within it. We also demonstrated that a hydrogenated diamond is extremely robust.
authors.affiliation: Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Chang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.forename: Ilan
authors.initials: I
authors.lastname: Ben-Zvi
authors.forename: Andrew
authors.initials: A
authors.lastname: Burrill
authors.forename: Jorg
authors.initials: J
authors.lastname: Kewisch
authors.forename: Triveni
authors.initials: T
authors.lastname: Rao
authors.forename: John
authors.initials: J
authors.lastname: Smedley
authors.forename: Erdong
authors.initials: E
authors.lastname: Wang
authors.forename: Erik M
authors.initials: EM
authors.lastname: Muller
authors.forename: Richard
authors.initials: R
authors.lastname: Busby
authors.forename: Dimitre
authors.initials: D
authors.lastname: Dimitrov