The TOF-ACC flight electronics for the fast trigger and time of flight of the AMS-02 cosmic ray spectrometer

The AMS-02 experiment has been installed in May 2011 on the international space station (ISS) where it will measure, with an unprecedented accuracy, cosmic rays up to the TeV energy region for several years. The AMS-02 time of flight (TOF) and the anti-coincide counters (ACC) sub-detectors provide respectively the fast trigger and the veto for the data taking to the experiment. The TOF measures the particle crossing time and the absolute charge with very high precision and provides the fast trigger to AMS-02, whereas the ACC detects and vetoes particles which enter the AMS-02 volume from outside of the main detector acceptance. The electronics of the AMS-02 TOF and ACC sub-detectors have been designed to operate in space for a very long time, in extreme conditions and without any human intervention. In this paper the main design concepts of the TOF-ACC electronics, the space qualification tests and the performance are presented. © 2012 Elsevier B.V.