Characteristic study of the internal target for the Double Hypernuclei physics at PANDA

The case of the internal target for the hypernuclear experiment of the PANDA (antiproton Annihilation at Darmstadt) Collaboration at the HESR (High Energy Storage Ring) of FAIR (Facility for Antiproton and Ion Research) is illustrated. The main aspects of the experiment designed for the production of Double Hypernuclei are initially summarized. The problems arising from the interaction of a solid internal target with an antiproton beam inside a ring are briefly discussed, together with the constraints in making such a set up. The design of material, shape and size of a target satisfying the experimental requirements is presented. The techniques used to produce a prototype of this target are illustrated. Then the results of the tests performed on the prototype to investigate the properties (purity, radiation hardness, structure modifications after shaping) are reported and the plan of the future activity is presented.