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 have developed is based on the use of a 10 x 10 anodes array placed behind two microchannel-plates assembly in a chevron arrangement. The spread of charge between MCP and the multianode is used to derive the position of ions striking the detector. Spatial coordinates can be calculated for multiple and simultaneous time-of-flight events. The procedure that we have used for the derivation of ions positions from charge measurement is given and preliminary results are described.