Experimental characterization of ion-irradiated tungsten fibers

In fusion reactors tungsten is exposed to high doses of neutron radiation, which causes an embrittlement of the material. The irradiation leads to microstructural damage and causes transmutation. The microstructural damage can be simulated by heavy ion irradiation. In this work, tungsten ion-radiation was used as an easy to control damage source. Fine grained drawn tungsten fibers with a diameter of 16 µm were used as sample material. Due to limited penetration depth of the ions, the fibers needed to be thinned to a diameter of 5 µm. Oriented towards previous investigations, irradiation experiments with several radiation doses were conducted on the thinned fibers. GIRAFFE, a newly developed device for tensile tests was qualified and used for the evaluation of the irradiated samples. After the tensile tests the diameter of the broken fibers were measured as an indication for their ductility. It was found, that radiation doses up to 10 dpa does not show a measurable influence on the ductility of tungsten fibers.