Electron beam collimation with a 40000 tip metallic double-gate field emitter array and in-situ control of nanotip sharpness distribution

The generation of highly collimated electron beams from a double-gate field emitter array with 40000 metallic tips and large collimation gate apertures is reported. Field emission beam measurements demonstrated the reduction of the beam envelope down to the array size by applying a negative potential to the on-chip gate electrode for the collimation of individual field emission beamlets. Owing to the optimized gate structure, the concomitant decrease of the emission current was minimal, leading to a net enhancement of the current density. Furthermore, a noble gas conditioning process was successfully applied to the double-gate device to improve the beam uniformity in-situ with orders of magnitude increase of the active emission area. The results show that the proposed double-gate field emission cathodes are promising for high current and high brightness electron beam applications such as free-electron lasers and THz power devices. DOI: https://doi.org/10.1063/1.4788998 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-93515 Published Version Originally published at: Helfenstein, P; Guzenko, V A; Fink, H W; Tsujino, S (2013). Electron beam collimation with a 40 000 tip metallic double-gate field emitter array and in-situ control of nanotip sharpness distribution. Journal of Applied Physics, 113(4):043306. DOI: https://doi.org/10.1063/1.4788998 Electron beam collimation with a 40000 tip metallic double-gate field emitter array and in-situ control of nanotip sharpness distribution P. Helfenstein, V. A. Guzenko, H.-W. Fink, and S. Tsujino Citation: Journal of Applied Physics 113, 043306 (2013); doi: 10.1063/1.4788998 View online: http://dx.doi.org/10.1063/1.4788998 View Table of