HIGH-RESOLUTION POSITRON-ANNIHILATION SPECTROSCOPY WITH A NEW POSITRON MICROPROBE

In cooperation with Zeiss/LEO GmbH, a monoenergetic positron source ha s been integrated in the electron optical system of a scanning electro n microscope by help of a magnetic prism, The electron optics serves b oth to image the specimen with electrons and to form a positron microb eam that allows local positron-annihilation measurements with a resolu tion in the micron range. The fatigue damage profile along the cross s ection of a copper plate after a three-point bending test has been inv estigated. The obtained S-parameter profile coincides well with the ex pected fatigue damage distribution. (C) 1997 American Institute of Phy sics.