Reduction of ion sputtering yield by special surface microtopography

It is demonstrated that by covering a tungsten surface with tungsten needles, the sputtering coefficient for He ions is reduced by a factor of 3 to 100. Also, this metal surface does not blister under He bombardment to doses of 2.8×1019 He/cm2, although a similar polished W surface blisters at 1/30 this dose. Sputtering yields have been determined for both monoenergetic and distributed energy He ion beams, and the angular distribution of sputtered ions is reported.