  We demonstrate the application of event-driven Timepix3-based detectors in
combination with a double-sided velocity-map-imaging spectrometer to record the
full 3D momentum of charged particles at the free-electron-laser facility
FLASH. We measured the XUV induced fragmentation of $\text{N}_2$ using 250 kHz
FLASH bursts with sub-pixel spatial resolution and up to 1.7~ns temporal
resolution for photoelectrons. To further demonstrate the capabilities of this
camera at even higher repetition rates we measured single-shot images of
He($1s$) photoelectrons for bursts with a repetition rate of 1 MHz. Overall,
with the Timepix3 camera we overcome limitations of standard-camera technology
for advanced-imaging experiments with requirements on high event-rates and high
spatio-temporal resolution.
