JGU logoThe Mainz Microtron MAMI consists of two sources for unpolarised and polarised electrons, followed by an injection linac, three consecutive racetrack-microtrons and a harmonic double sided microtron. The racetrack microtrons, also known as MAMI A & B, accelerate the electrons in steps of 15 MeV to an energy of up to 885 MeV.

The final accelerator stage, named MAMI C, is a harmonic double sided microtron which increases the energy up to 1604 MeV.The beam at MAMI excels by its reliability (> 80% beam on target, about 6600 hours of beam per year on the long-term average), a very small diameter (0.1 mm), a tiny halo (only about 10-5 of the intensity is outside a diameter of 1 mm) and a very good energy definition (10-6 long-term stability). The most important quality, however, is the continuous wave operating mode. With such a beam it is possible to detect several coincident particles simultaneously with a high signal to noise ratio. This allows high beam currents (up to 100 μA to be used) and thus measurements of small coincident cross-sections containing significant and well defined observables. The quality of this accelerator is paralleled in the world only by CEBAF (Continuous Beam Electron Accelerator Facility) of the Thomas Jefferson Laboratory in Newport News, Virginia, USA.

However, CEBAF covers the energy range from about 1.5 GeV to 6 GeV and is striving to increase its energy to 12 GeV. Therefore, MAMI is unique in the energy range it covers and with the beam quality and availability it offers.


The HadronPhysics3 project is supported by the European Union
under the 7th Framework Capacities Programme in the area of Research Infrastructures (RI).