HIVIPP deposition and characterization of isotopically enriched 48Ti targets for nuclear cross-section measurements

Abstract

Thin targets of isotopically enriched 48Ti metallic powder on Al foil substrates for the nuclear cross-section measurements were manufactured using the HIgh energy VIbrational Powders Plating method in vacuum. The target areal thickness of 0.2–2 mg/cm2 was achieved as measured by weighing as well as by Elastic Backscattering Spectroscopy (EBS) analysis. The quality of the targets, in particular the deposit uniformity, was evaluated by Scanning Electron Microscope (SEM) assisted by the Energy Dispersive Spectroscopy (EDS). The microstructure of the HIVIPP deposited targets was analyzed for the first time. SEM analysis showed that the coating microstructure was strongly related to the original powder microstructure. It was also observed that the coating was not a powder monolayer. The smaller powder particles, which were the first to move in the electric field, remained attached to the substrate and created the first layers of the deposit. Further layers of bigger particles were then attached to the first layer. The information about the deposit microstructure was utilized to model the EBS analysis results. The subset of the prepared 48Ti enriched targets was successfully used for the nuclear cross-section measurement campaign up to 40 MeV using the proton beam (115 nA) available at the C70 cyclotron in ARRONAX (Nantes, France).