ON THE DEVELOPMENT OF A 3D TOMOGRAPHIC ATOM-PROBE

The development of a three-dimensional atom-probe relies on the design of a position sensitive detector. The multidetection system that we h ave developed is based on the use of a 10 x 10 anodes array placed beh ind two microchannel-plates assembly in a chevron arrangement. The spr ead of charge between MCP and the multianode is used to derive the pos ition of ions striking the detector. Spatial coordinates can be calcul ated for multiple and simultaneous time-of-flight events. The procedur e that we have used for the derivation of ions positions from charge m easurement is given and preliminary results are described.