Mainz Microtron
MAMI is the core of an experimental facility for particle, nuclear and X-ray radiation physics at the Johannes Gutenberg University in Mainz (Germany).
The scientific research at MAMI focusses on the investigation of the structure and dynamics of hadrons, particles consisting of quarks and gluons bound by the strong force.
The most important hadrons are protons and neutrons, the basic constituents of atomic nuclei and, therefore, the building blocks of ordinary matter.
Due to constant, homogeneous magnetic bending fields the length of the beam path is increasing with energy after each turn.
This microtron scheme makes efficient use of the rf power and the inherent strong longitudinal phase focussing guarantees excellent beam quality and stability.
To compensate for the strong vertical defocusing due to the 45° pole-face inclination between the magnets, these dipoles incorporate an appropriate field gradient normal to this pole edge.
The mean availability of the beam for experiments (> 80%) is at a very high level, a clear demonstration that the HDSM scheme is as reliable and stable as the RTM cascade.
The largest experimental hall of the MAMI accelerator complex houses three high-resolution, focussing magnetic spectrometers operated by the A1 Collaboration.
) together with the large acceptance in solid angle (up to 28 msr) and in momentum (up to 25%) makes this setup ideal for electron scattering in coincidence with hadron detection.
A fourth spectrometer (KAOS/A1), covering high momenta with a moderate path length for the detection of kaons, is currently in the commissioning phase.
The main physics goals are: The A2 Collaboration studies reactions induced by high-energy photons incident on nucleons or nuclei.
A beam of photons with known energy and flux is produced via bremsstrahlung using a dedicated tagging spectrometer provided by the University of Glasgow.
For charged-particle tracking and identification two layers of coaxial multi-wire proportional chambers and a barrel of 24 scintillation counters surrounding the target are installed inside the cavity of the Crystal Ball sphere.
The A4 Collaboration measures small asymmetries in the cross-section of elastic scattering of polarized electrons off an unpolarized target, basically hydrogen or deuterium.
The scattered electrons are measured by a total absorbing, segmented lead fluoride calorimeter, which deals with event rates of about 100 MHz.
The degree of polarization of the electron beam is measured by a laser Compton backscatter polarimeter simultaneously with to the main experiment.
