Study, fabrication and test of a special cooling system for targets submitted to intense ion beams

In Nuclear Physics, the cross-section measurement of rare reactions requires very intense beams, which deposit large amount of heat inside the target. Sometimes, the target material chosen for a given reaction has poor thermal properties; therefore, the heat produced by the beam inside the target must be efficiently dissipated. In the present work, the use of Highly Oriented Pyrolytic Graphite as a support for the target is proposed. Its high thermal conductivity allows to quickly transfer the heat to the cold sample holder. The case of the NUMEN project, which will use very intense ion beams on thin targets, is considered. The temperature distribution inside both the target and the graphite has been calculated for several materials. A numerical technique, based on a MATLAB code, was tested in some analytical cases and then used to evaluate the time and spatial distributions of the temperature in the system. The first target prototypes have been produced and then characterized by Field Emission Scanning Electron Microscopy analysis.