Target Manipulation in Nuclear Physics Experiment with Ion Beams

The NUMEN project at Laboratori Nazionali del Sud of INFN studies the nuclear matrix elements of Double Charge Exchange reactions between some particular nuclei. This information will be helpful in studying the Neutrinoless Double Beta decay. Because of the very low cross-sections of such reactions, high statistics must be acquired using very intense ion beams coupled with thin targets in order to get a good resolution in energy measurements. Since the target is irradiated with low energy and intense ion beams the crucial problems are the large amount of released heat and the activation of the material. To cope with the first problem isotopes are evaporated on a graphite substrate with high thermal conductivity that will be cooled down using a cryocooler. The second issue demands for an automatic system for the target handling during the data taking of the experiment. Positioning of the target-holder with appropriate precision and contact force is a special requirement, while all materials have to be selected to suit both the large temperature range and the foreseen radiation level. This work focuses on the automatic system for target manipulation, describing its design characteristics to cope with such particular working condition and to be integrated in the experiment.