Thermal treatments and characterizations of pellets for SPES direct target

The production of targets for the generation of Radioactive Ion Beams (RIB) characterized by high power resistance, fast diffusion release, high permeability and high ionization yield is a topic of great interest and the research on this field is currently very lively. In this work, the synthetic route where carburization of a suitable precursor compound of lanthanum is obtained by mixing the compound with a proper amount of graphite and a binder, followed by thermal treatment has been chosen. In order to increase the porosity of the final material a novel technique, which makes use of lanthanum oxalate as starting precursor, has been tested. A series of pellets with diameter of 13 mm and thickness of 1 mm were obtained by mixing lanthanum oxide and graphite in a mortar and the cohesion of the powders was assured by the addition of a phenolic binder. Thermal treatments on the pellets were performed in Lindberg furnace, equipped with an alumina tube, and in Astro furnace, equipped, with a graphite chamber. In a first run, a thermal treatment has been performed on a pellet based on lanthanum oxide and graphite previously decarbonated and dehydrated in a muffle furnace at 800 ◦ C. The sample was thereafter heated in vacuum up to 1500 ◦C and in argon atmosphere until 1800◦C. The success of the carburization process was confirmed by the appearance of the pellet after the treatments