Development of radioactive beams at ALTO: Part 1. Physicochemical comparison of different types of UCx targets using a multivariate statistical approach

TL;DR

This study compares different UCx target microstructures using multivariate analysis to identify optimal synthesis methods for improved fission product release in ISOL applications.

Contribution

It introduces a multivariate statistical approach to objectively analyze UCx target microstructure variations and identifies key synthesis parameters for optimal target properties.

Findings

Carbon nanotubes as carbon source improve microstructure stability

New mixing method reduces sintering and grain size

High porosity with small, well-distributed pores achieved

Abstract

The optimization of the microstructure of the UCx target is a key point since many years in the field of ISOL method. The ultimate goal is to facilitate the release of the fission products, especially those with short half-lives. Fourteen UCx samples were synthetized from different uranium and carbon sources using three mixing protocols. All carburized samples were systematically characterized in terms of nature and proportion phases, grain and aggregate size, open and close porosity proportion and open pore size distribution. Our results were analysed using a multivariate statistical approach in order to remove any subjective bias. Strong correlations between the physicochemical characteristics of the samples as well as the impact of the synthesis process have been highlighted. In particular, using carbon nanotubes as carbon source combined with a new method of mixing is the key parameter to limit the sintering and to obtain samples with small grains and a high porosity well distributed over small pores. Moreover the microstructure obtained proved to be stable at high temperature.