Picosecond electron deflectometry of optical-field ionized plasmas

Optical-field ionized plasmas are of great interest owing to their unique properties and the fact that they suit many applications, such as the study of nuclear fusion(1), generation of energetic electrons(2-5) and ions(6,7), X-ray emission(8,9), X-ray lasers(10-12) and extreme-UV attosecond pulse generation(13). A detailed knowledge of the plasma dynamics can be critical for optimizing a given application. Here we demonstrate a method for real-time imaging of the electric-field distribution in optical-field ionized plasmas with ultrahigh temporal resolution, yielding information that is not accessible by other methods. The technique, based on electron deflectometry, yields images that reveal a positively charged core and a cloud of electrons expanding far beyond the Debye length.