Several novel diagnostic systems based on the detection of coherent THz radiation are
presented. The investigation of the photon beam properties allow for bunch-by-bunch and
turn-by-turn diagnostics of the emitting electron bunches in the accelerator. It is used for
time-resolved studies of the micro-bunching instability. Accompanying simulations with Inovesa
show a good agreement with the measurement which enhances the knowledge of the physics behind
the micro-bunching instability.
