Micron-bubble formation on polycrystal tungsten due to low-energy and high-flux helium plasma exposure

Abstract

Surface modification of polycrystal tungsten due to low-energy and high-flux helium plasma exposure was investigated. Micron-sized holes and bubbles were formed on the surface at a surface temperature of 2200 K even when the incident ion energy of helium was 10 eV. Hole formation was significantly reduced on the surface when the incident ion energy of helium was around S eV and no surface modification was seen at less than 5 eV. Coalescence of micron-sized helium bubbles was observed in the cross section of a W sample. ©2005 The Japan Institute of Metals tungsten, helium plasma, hole, helium bubble.