The MAGIX experiment is a versatile fixed target experiment, designed to perform a rich physics program including high luminosity searches for rare events and precision measurement of nuclear observables in the range between a few MeV and about 100 MeV, exploiting the intense electron beam of the MESA accelerator. The relatively low beam energy limits the energy of the scattered particle and the whole system must be optimized to limit the interaction of the secondary particle before their detection.
In many of the foreseen applications the most important observables to measure are the momentum and scattering angle of the produced particles. The high intensity of the primary electron beam allows us to reduce the detector acceptance to improve the measurement quality, thus we choose an experimental setup constituted by 2 magnetic spectrometers with high precision gas detectors on the focal plane.
Due to the limited energy of the primary electron beam, the interactions of the secondary particles prior to their detection must be accurately minimized. In particular, the target system and its interface with the detector are carefully designed to limit to the minimum any unwanted interaction but allowing instantaneous luminosity of the order of 1035cm-2s-1.
The very high luminosity that can be achieved at the MAGIX interaction point, combined with the precision detector system of the experiment makes MAGIX an ideal setup to search for extremely rare interactions of “dark particles” in the energy range between a few MeV and about 100 MeV. The most relevant example of this category of processes is the search for “Dark Photons” in the electron-nucleus scattering.
The physics reach of the MAGIX experiment is not limited to those rare searches but extends also to the precision measurement of nuclear observables where, due to the high instrumental accuracy of the TARDIS system we can achieve competitive results in a broad range of measurements.
The target system of the MAGIX experiment is based on a windowless gas stream which makes it possible to reach luminosity of the order of 1035 cm-2 s-1 while keeping the beam quality good enough so it can be recaptured by the machine after the interaction.
To layouts are currently under development: a jet target which provides a dense but thin gas stream perpendicular to the beam direction and a tube target that, working at lower pressures and densities, allows to use polarized nuclei as targets, a relevant feature for many nuclear physics experiments.
The particles produced in the target region will be collected in a pair of identical magnetic spectrometers, pivoting around the centre of the target. Each spectrometer is composed by a quadrupole and by a dipole magnet which focus particles of different momenta incoming from the interaction point to different positions on the focal plane.
On the focal plane a set of high resolution gas detector allow to reconstruct the kinematics of the interaction vertex.