Although radio frequency (RF) technology is routinely employed for controlling high-energy pulses of electrons, corresponding technology has not been developed at beam energies below several kiloelectronvolts. In this work, we demonstrate transverse and longitudinal phase-space manipulation of low-energy electron pulses using RF fields. A millimeter-sized photoelectron gun is combined with synchronized streaking and compression cavities driven at frequencies of 0.5 and 2.5 GHz, respectively. The phase-controlled acceleration and deceleration of photoelectron pulses is characterized in the energy range of 50–100 eV. Deflection from a transient space-charge cloud at a metal grid is used to measure a fourfold compression of 80−eV electron pulses, from τ=34 to τ=8 ps pulse duration.

We demonstrate radio-frequency compression and streaking of low-energy electron pulses for ultrafast diffraction from surfaces with few-ps time resolution.

We demonstrate the capability of ultrafast low-energy electron diffraction to resolve phase-ordering kinetics and structural phase transitions on their intrinsic time scales with ultimate surface sensitivity.

We report the development of an ultrafast miniaturized pulsed electron gun for the implementation of time-resolved low-energy electron diffraction. This electron gun consists of a nanotip photocathode and an einzel lens for beam collimation. Assembly and electrical contacting of the gun is achieved in a multistep process involving photolithography and focused-ion-beam etching. First applications in a backscattering geometry were demonstrated with a temporal resolution of 1 ps at an electron energy of 80 eV.