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.