Development of Surface Morphologies on Single Crystal Tungsten Irradiated with 30 keV Helium Ions at 900ºC

Abstract

Single crystal tungsten samples with (110) and (100) surface orientations were irradiated with 30 keV He⁺ at 900ºC to fluences of 3×10¹⁷ to 1×10¹⁹ He⁺/cm² at normal incidence. The samples exhibited various microstructures and increasing sample mass loss as a function of increasing fluence for both cases. Pores observed on the sample surface at each fluence were ~45 nm in diameter merging into larger surface pores up to ~800 nm in length at the highest irradiation fluence of 1×10¹⁹ He⁺/cm².

Keywords:

• Crystal orientation
• fusion material
• helium ion irradiation
• plasma-facing material
• tungsten

Acknowledgments

Funding for this research was provided through the University of Wisconsin–Madison Graduate Engineering Research Scholars Fellowship, and the Grainger and Greatbach Foundations. The authors gratefully acknowledge use of facilities and instrumentation at the University of Wisconsin–Madison Wisconsin Centers for Nanoscale Technology (wcnt.wisc.edu) partially supported by National Science Foundation through the University of Wisconsin Materials Research Science and Engineering Center (DMR-1720415).