  The small time gap of synchrotron radiation in conventional multi-bunch mode
(100-500MHz) is prohibitive for time-of-flight (ToF) based electron
spectroscopy. Even the new generation of delay-line detectors with improved
time resolution (<100ps) yields only 20-100 resolved time slices within a
2-10ns gap. Here we present two techniques of implementing efficient ToF
recording at sources with high repetition rate. A fast electron-optical beam
blanking unit with GHz bandwidth, integrated in a photoelectron momentum
microscope, allows chopping the photon-pulse train to any desired repetition
period. Aberration-free momentum distributions have been recorded at chopped
pulse periods of 5MHz (at MAX II) and 1.25MHz (at BESSY II). The approach is
benchmarked against the alternative way of implementing a dispersive element,
e.g. a hemispherical analyzer, in the electron optics. Both approaches,
chopping in the time domain as well as bandpass pre-selection in the energy
domain, can enable efficient ToF spectroscopy, spectroscopic real-space imaging
and momentum microscopy with few-meV resolution using 100-500MHz Synchrotron
radiation, highly-repetitive lasers or cavity-enhanced high-harmonic sources.
For comparison, we show results recorded at BESSY II with a parasitic 4-bunch
island-orbit pulse train, coexisting with the 500MHz filling pattern on the
main orbit.
