Ion-induced secondary electron emission coefficient (gamma) of bulk-MgO single crystals

The ion induced secondary electron emission coefficient gamma of bulk-MgO s ingle crystal has been measured by the gamma-focused ion beam system. It is found that the bulk-MgO single crystal with (111) orientation has the high est gamma from 0.08 up to 0.21, and the gamma values are in the order of th e crystallinities, (111) > (200) > (220) for operating Ne+ ions ranging fro m 50 eV to 300 eV in this experiment. These results are consistent with our previous reports for MgO protective layers with respective orientations of (111), (200), and (220).