Matthieu Lebois | Searcharxiv

arXiv2025

Impact of UC2, UC, UBC and UB2 target compositions on the release of fission products

The release properties of 4 targets (UC2, UC, UBC, UB2) were measured for 11 elements (Kr, Sr, Ru, Sn, Sb, Te, I, Cs, Ba, La, and Ce) using an off-line technique. The crystal packing fraction and the size of the studied element play a key role in the release process. However, physicochemical properties are also involved, notably melting and boiling points in vacuum and the minimal oxidation state. Principal component analysis was used to investigate the interrelationships between the physicochemical properties of fission products (from Fe to Dy) and the observed releases, thereby enabling predictions to be made about the release properties of the four crystallic configurations for elements that are inaccessible in off-line experiments.

cond-mat.mtrl-sci↗

arXiv2022

Extraction of diffusion coefficients from the study of Rb release in different carbon catchers

New Target-Ion Source Systems combining a target and a catcher material are developed in the radioactive beam community, in particular at GANIL, in order to maximise the yield of very short lived atoms by minimizing the atom-to-ion transformation time. The aim of this study is to characterize the release properties of 81Rb collected on two graphite catchers and two carbon nanotube catchers. The release fractions were measured at various catcher-heating temperatures and then compared to the analytical expressions relevant to each catcher. This comparison led to the extraction of the pre-exponential factor (D0) and the activation energy (Eact) involved in the diffusion coefficient of Rb for three carbon microstructures. All these data allowed to define an ideal catcher which could be made of aligned carbon nanotubes of small diameter and oriented in order to collect all the 81Rb atoms produced by the target but also to release them efficiently.

cond-mat.mtrl-sci↗