INFLUENCE OF SURFACE-MORPHOLOGY ON THE LOW-ENERGY HYDROGEN-ION EROSION YIELDS OF BERYLLIUM

It has been found that the surfaces of both vacuum-deposited and hot-pressed beryllium develop closely spaced, high angle cones under extended low energy (1000 eV) hydrogen ion bombardment. This needlelike eroded surface morphology results in a lowering of the 1000 eV hydrogen ion erosion yield by about 30-40% compared to the uneroded material. Measured erosion yields for both hot-pressed and vacuum-deposited beryllium are: Be (virgin, 1000 eV) = ~0.04 atoms/ ion; Be (eroded, 1000 eV) = 0.027 atoms/ion; Be (virgin, 250 eV) = ~0.011 atoms/ion; Be (eroded, 250 eV) = 0.0091 atoms/ion. © 1979.