Investigation of silicon sensors for their use as antiproton annihilation detectors

We present here a new application of silicon sensors aimed at the direct detection of antinucleons annihilations taking place inside the sensor׳s volume. Such detectors are interesting particularly for the measurement of antimatter properties and will be used as part of the gravity measurement module in the AEg¯IS experiment at the CERN Antiproton Decelerator. One of the goals of the AEg¯IS experiment is to measure the gravitational acceleration of antihydrogen with 1% precision. Three different silicon sensor geometries have been tested with an antiproton beam to investigate their properties as annihilation detection devices: strip planar, 3D pixels and monolithic pixel planar. In all cases we were successfully detecting annihilations taking place in the sensor and we were able to make a first characterization of the clusters and tracks.