Strong-Field Photoemission Experiment using Diamond Field Emitter Arrays

In this paper, we present the results of experimental observation of strong-field photoemission from a diamond field-emitter array (DFEA) illuminated by a focused laser beam with 1035 nm wavelength. Having the advantage of high emission current and low beam emittance, DFEAs can emit ultra-short high charge electron bunches required for multiple accelerator applications. We have performed strong-field photoemission experiment at a newly commissioned test stand at Los Alamos National Laboratory (LANL). We triggered a diamond tip with a typical apex of 10-20 nm with 300 femtosecond (fs) laser pulses to produce electron beam emission. The profile of the emitted beam was determined by the analysis of an image formed on the fluorescent screen after a microchannel plate (MCP) intensifier; beamlets corresponding to emission from the pyramid sides and nano-tip were identified. Image analysis of the beamlet associated with emission from the nano-tip was conducted to understand dependencies of intensities of the emission on polarization of the laser's light and its peak intensity.