Atomic mechanism of radiation-induced erosion of field electron emitters

The features of erosion of the surface of field electron emitters bombarded by helium and neon ions were studied. Experiments showed that ion bombardment produced tungsten atom transport, the number of atoms transported being proportional to the ion fluence. Analysis of ion bombardment-induced atomic-scale surface roughness showed evidence of a non-dynamic surface atom displacement for primary ion energies below a threshold for stable Frenkel pair formation and cathode sputtering. A quasi-static mechanism of surface erosion is considered, according to which the process is related to the displacement of metal atoms into low-coordinated positions upon evolution of the energy of formation of interstitial inert gas atoms. Copyright (C) 2004 John Wiley Sons, Ltd.