EVOLUTION OF VACANCY DEFECTS IN THE SURFACE-LAYERS OF A METAL IRRADIATED WITH A PULSED ELECTRON-BEAM

The distribution of vacancy defects in the surface layers of alpha-Fe after irradiation with a high-current pulsed electron beam is studied experimentally by unique nuclear-physical methods - low-energy positro n annihilation, Rutherford backscattering (RES), and proton-induced x- ray emission (PIXE). Regions with low local density, which are sources of crater formation on the surface of the irradiated sample, are obse rved by scanning a proton microbeam. Positron lifetime measurements re veal that as the electron beam power increases, nonequilibrium vacanci es tend to be captured by carbon impurity atoms. (C) 1997 American Ins titute of Physics.