Dresden 2017 – scientific programme

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DS: Fachverband Dünne Schichten

DS 44: Postersession II

DS 44.48: Poster

Thursday, March 23, 2017, 17:00–19:00, P1C

Ultrafast laser-triggered electron emission from diamond coated metal tips — •Alexander Tafel, Peter Hommelhoff, and Jürgen Ristein — Department Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen

Sharp metal tips are widely used in electron microscopy as cold cathodes utilizing the outstanding beam quality of field emitted electrons from a nm sized virtual source. Nanocrystalline diamond with negative electron affinity exhibits excellent electron field emission properties and allows nm thin coating. The combination of the unique properties of sharp tips and nanodiamond are used in this work for building a high brightness femtosecond electron source.

Tungsten tips are etched electrochemically with resulting tip radii < 20 nm. Nanodiamond seeding is used to achieve high nucleation densities required for thin but dense films. Diamond films are grown using microwave enhanced chemical vapour deposition.

Ultrafast electron emission from diamond coated samples is investigated by few-cycle infrared pulses. Here, we present first experimental results and compare electron emission from diamond coated tips to bare tungsten tips.

The goal of this research is to develop a source of ultrashort and intense electron bunches for use in 4-D electron microscopy, dielectric laser acceleration and ultrafast electron diffraction.