In the MESA (Mainz Energy-Recovering Superconducting Accelerator) accelerator, electrons are first pre-accelerated to an energy of 5 MeV using the MAMBO linear accelerator before entering the main accelerator, where they are accelerated to up to 155 MeV, depending on the operating mode. The special thing about MESA is that the accelerator implements the Energy Recovery Linac (ERL) concept, which was only developed a few years ago. This means that the energy of a large proportion of the accelerated electrons can be recovered with the aid of so-called superconducting cavity resonators, which means that MESA is significantly more energy-efficient than conventional accelerators and can achieve an extremely high beam intensity with the net energy input: Up to 6*10¹⁶ electrons per second (corresponding to 10 milliamperes of electron current) will hit the sample under investigation, increasing the chance of detecting very rare events. In addition, MESA will have a very high beam quality, as the energy of all electrons is very homogeneous. Taken together, MESA will provide optimal conditions for carrying out experiments with very high precision – e.g. in terms of energy resolution or event rate.

You can also find a visualization in the following explanatory video.