Development of the ATHENA vertex detector

The ATHENA experiment [2000] is a new experiment at the antiproton decelerator (AD) at CERN. Its goal is the production, detection and spectroscopic investigation of antihydrogen in a magnetostatic trap. The experimental technique used will allow to compare the atomic structure of matter and antimatter to a level of 10/sup -15/ and thus provides a test for CPT conservation. In order to unambiguously detect the annihilation of antihydrogen atoms, a detector system consisting of double sided silicon strip detectors and CsI-crystals was developed. The complete vertex detector has to be operated at 77 K. An overview of the experiment is given and the development of the vertex detector is presented. (4 refs).