Gigahertz streaking and compression of low-energy electron pulses.

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.