Erosion of Copper Target Irradiated by Ion Beam

TL;DR

This study investigates copper target erosion under deuterium ion beam irradiation, revealing sputtering as the main erosion process and the formation of carbon-rich tadpole-shaped structures in surface cracks.

Contribution

It provides new insights into erosion mechanisms and surface morphology changes of copper under ion beam irradiation at high fluences.

Findings

Physical sputtering dominates erosion.

Formation of tadpole-shaped structures with high carbon content.

Surface cracks host these unique structures.

Abstract

Erosion of copper target irradiated by deuterium ion beam with ultimate fluence is studied. The target originally destined for neutron generation represents bulk copper substrate covered by 3-\mum titanium layer. The target was irradiated by deuterium ion beam generated in Bayard-Alpert type ion source with energy of ions 17.5 keV/nuclear. Maximal fluence in the center of the target achieves 2.5x10^23atoms/cm^2. Measurements of the profile of irradiated target and estimation of fluence shows that physical sputtering is a dominating process that determines the target erosion Most interesting feature is growth of \mum-size tadpole-shaped structures, localized in the cracks of the surface. RFA analysis of these structures showed extremely large (up to 60%at.) carbon content.