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

Abstract

Some of these parameters are defined by the installation used: this is the case in particular of the incident beam. At ALTO we use an electron beam of 50 MeV energy and 10 μA intensity to induce photofission [1].

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

“…In order to compare the release properties of the studied catchers, release efficiencies are more convenient than released fractions. Both depend on the diffusion coefficient and can be calculated in the frame of models describing diffusion in specific media: in a sheet, a cylinder, a sphere or a fibre [12]- [14]. The choice of the medium in which the diffusion takes place will be made according to the structural properties of the different catchers.…”

“…One can wonder how these properties will interact in the release process and whether one of the components (diffusion or effusion) will be predominant in the overall process. To answer this question,the analysis of the CNTv released fractions was performed using as model the diffusion in a cylinder [12], [14] with the same radius and length as the CNTs making up the carpet (R = 5 nm and L = 90 µm). Choosing this model means that the release of the atoms out of the catcher is only governed by the diffusion out of the cylinder material, and that the contribution of the effusion between the cylinders is negligible.…”