Towards a novel THz-based monitor for sub picosecond electron bunches working at MHz repetition rates and low bunch charges

Femtosecond level diagnostic and control of sub-picosecond electron bunches is an important topic in modern accelerator research. At the same time new quasi-cw linear electron accelerators are the drivers of many future 4th Generation lightsources such as X-ray free electron lasers. A high duty cycle, high stability and online pulse to pulse diagnostic of these new accelerators are crucial ingredients to the success of these large scale facilities. A novel THz based online monitor concept is presented that has the potential to give access to pulse to pulse information on bunch form, arrival time and energy at high repetition rate and down to sub pC charges. It has been shown experimentally that pulse to pulse arrival time measurements can be used to perform high temporal resolution and dynamic range experiments, removing the influence of synchronization problems between the accelerator and external laser systems.