Resonating Electrostatically Guided Electrons.

An essential component for quantum-enhanced measurements with free electrons is an electron resonator. We report stable guiding of free electrons at 50 eV energy for up to seven round trips in a linear autoponderomotive guiding structure, which is realized with two microstructured printed circuit boards that generate the required electromagnetic fields. Free electrons are laser triggered from a sharp tungsten needle tip and coupled in at the front of the electron resonator with the help of sub-nanosecond-fast switchable electron mirrors.

Precise, subnanosecond, and high-voltage switching enabled by gallium nitride electronics integrated into complex loads.

In this work, we report the use of commercial gallium nitride (GaN) power electronics to precisely switch complex distributed loads, such as electron lenses and deflectors. This was accomplished by taking advantage of the small form-factor, low-power dissipation, and high temperature compatibility of GaN field effect transistors (GaNFETs) to integrate pulsers directly into the loads to be switched, even under vacuum. This integration reduces parasitics to allow for faster switching and removes the requirement to impedance match the load to a transmission line by allowing for a lumped element approximation of the load even with subnanosecond switching.

Electrostatic electron mirror in SEM for simultaneous imaging of top and bottom surfaces of a sample.

The use of electron mirrors in aberration correction and surface-sensitive microscopy techniques such as low-energy electron microscopy has been established. However, in this work, by implementing an easy to construct, fully electrostatic electron mirror system under a sample in a conventional scanning electron microscope (SEM), we present a new imaging scheme which allows us to form scanned images of the top and bottom surfaces of the sample simultaneously. We believe that this imaging scheme could be of great value to the field of in-situ SEM which has been limited to observation of dynamic changes such as crack propagation and other surface phenomena on one side of samples at a time.