# Synthesis and Characterization of Nanostructured Thorium Carbide for Radioactive Ion Beam Production

## TL;DR

Researchers created nanostructured thorium carbide pellets for use in producing radioactive ion beams, which could improve the extraction of short-lived radioisotopes.

## Contribution

The novel synthesis method combines thoria nanoparticles and carbon nanotubes to create a new target material for radioactive ion beam production.

## Key findings

- The final thorium carbide pellets showed minimal oxide precursor traces.
- Carbon nanotubes remained intact and may enhance radioisotope release times.
- The material is suitable for efficient extraction of short-lived radioisotopes.

## Abstract

Thorium carbide (ThC2±x) nano-structured thin disc-like pellets were produced from thoria nanoparticles (ThO2-NP) and multi-walled carbon nanotubes (MWCNT). These composites are to be studied as a target material candidate for radioactive ion beam (RIB) production via nuclear reactions upon impact with high-energy proton beams on a stack of solid pellets. The ThO2-NP precursor was produced via precipitation of thorium oxalate from a thorium nitrate solution with oxalic acid and subsequent hydrothermal oxidation of the oxalate, creating the thoria nanoparticles. The ThO2-NP were then mixed with MWCNT in isopropyl alcohol and sonicated by two different methods to create a nanoparticle dispersion. This dispersion was then heated under medium vacuum to evaporate the solvent; the resulting powder was pressed into pellets and taken to an inert-atmosphere oven, where it was heated to 1650 °C and carbothermally reduced to ThC2±x. The resulting pellets were characterized via XRD, SEM-EDS, and Raman spectroscopy. The resulting thorium pellets exhibited, at most, trace levels of the oxide precursor. Furthermore, the nanotube structures were still present in the final product and are expected to contribute positively towards faster radioisotope release times by lowering isotope diffusion times, which is required for the efficient extraction of the shortest-lived (<1 s half-life) radioisotopes.