Technique for full surface examination of small spheres in the scanning electron microscope

In response to the increasing severity of target surface finish requirements for laser fusion experiments, it has become necessary to examine spherical targets in the Scanning Electron Microscope prior to laser irradiation on an orderly nondestructive basis. A new sample manipulation technique has been developed which rolls a thin wall sphere through 4π steradians without damage and allows easy recovery by placing the sphere between two parallel plane surfaces formed in silicone rubber on the ends of two 0.9 mm capillaries. Mechanical slides, actuated by normal stage controls, cause the capillaries in contact with the sphere to translate laterally and roll the ball. Using theta Z and theta Y motions, the entire surface of the sphere can be brought into a position for examination. With the capillaries oriented for best secondary electron collection and conductively coated, resolutions comparable with traditional mounting techniques are attained. A side looking tilted crystal Si(Li) detector has been incorporated to increase the utility of the system and allow simultaneous EDX microanalysis