An off-line method to characterize the fission product release from uranium carbide-target prototypes developed for SPIRAL2 project

Characterization of uranium carbide target materials to produce neutron-rich radioactive beams

“…Radioactive ions beams (RIB) intensities can be increased by improving the release efficiencies of UC x fission targets which appear clearly correlated to the microstructure of the target material as we have previously shown in the framework of the SPIRAL2 project [7]. This study was dedicated to the development of dense and porous samples, two properties a priori antagonistic but necessary to increase respectively the amount of fission fragments produced and their diffusion out of the target.…”

“…Finding optimal properties of the uranium refractory compound target materials constitutes a key ingredient for the production of a wide variety of isotope beams using the ISOL (Isotope Separator Online) technique. Different developments have been achieved in various facilities [1][2][3] and today uranium carbides with an excess of graphite (with variable stoichiometries, UC x , since uranium dicarbide UC 2 and uranium monocarbide UC phases can be both stabilized depending on the amount of graphite added) are used by the different operating facilities throughout the world [4][5][6][7][8].…”

Uranium Carbide Fibers with Nano-Grains as Starting Materials for ISOL Targets

“…In this case, the x and y dimensions are in the µm or nm scale, while the z dimensions can be much larger. A high porosity and a large surface-to-volume ratio in the fiber-based materials can result in a quick release of radioisotopes [ 15 ]. Fibers are obtained from polymers, their entanglement properties allowing the preparation of very long and thin samples.…”

Influence of density and release properties of UCx targets on the fission product yields at ALTO

“…Figure 2 shows that the photon distributions obtained in both cases are very similar. The fission rates obtained per cm 3 and per electron amount respectively to 2.42×10 -4 and 2.94×10 -4 with and without converter for a 25 MeV electron beam and to 9.18×10 -4 and 9.92×10 -4 with and without converter for a 50 MeV electron beam. The presence of a 2 mm thick tungsten converter reduces the number of fissions, but its influence is much less significant with higher beam energy.…”

“…In recent years, at the ALTO facility, we have conducted studies to understand and determine the factors that improve the release efficiency of ISOL targets. A systematic study on synthesis parameters (milling and mixing of precursor powders, pressing, carburation) led to the development of nanostructured-target synthesis protocols [3]- [8].…”