title: Surface-plasmon resonance-enhanced multiphoton emission of high-brightness electron beams from a nanostructured copper cathode.
abstract: We experimentally investigate surface-plasmon assisted photoemission to enhance the efficiency of metallic photocathodes for high-brightness electron sources. A nanohole array-based copper surface was designed to exhibit a plasmonic response at 800 nm, fabricated using the focused ion beam milling technique, optically characterized and tested as a photocathode in a high power radio frequency photoinjector. Because of the larger absorption and localization of the optical field intensity, the charge yield observed under ultrashort laser pulse illumination is increased by more than 100 times compared to a flat surface. We also present the first beam characterization results (intrinsic emittance and bunch length) from a nanostructured photocathode.
authors.affiliation: Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Li
authors.affiliation: Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA.
authors.forename: H
authors.initials: H
authors.lastname: To
authors.affiliation: Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA.
authors.forename: G
authors.initials: G
authors.lastname: Andonian
authors.affiliation: Advanced Light Source Division, LBNL, Berkeley, California 94720, USA.
authors.forename: J
authors.initials: J
authors.lastname: Feng
authors.affiliation: Advanced Light Source Division, LBNL, Berkeley, California 94720, USA.
authors.forename: A
authors.initials: A
authors.lastname: Polyakov
authors.affiliation: Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Scoby
authors.affiliation: Advanced Light Source Division, LBNL, Berkeley, California 94720, USA.
authors.forename: K
authors.initials: K
authors.lastname: Thompson
authors.affiliation: Advanced Light Source Division, LBNL, Berkeley, California 94720, USA.
authors.forename: W
authors.initials: W
authors.lastname: Wan
authors.affiliation: Advanced Light Source Division, LBNL, Berkeley, California 94720, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Padmore
authors.affiliation: Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA.
authors.forename: P
authors.initials: P
authors.lastname: Musumeci