Response of windowless silicon avalanche photo-diodes to electrons in the 90–900 eV range

We report on the characterization of the response of windowless silicon avalanche photo-diodes to electrons in the 90-900 eV energy range. The electrons were provided by a monoenergetic electron gun present in the LASEC laboratories of University of Roma Tre. We find that the avalanche photo-diode generates a current proportional to the current of electrons hitting its active surface. The gain is found to depend on the electron energy Ee, and varies from 2.147±0.027 (for Ee=90 eV) to 385.8±3.3 (for Ee=900 eV), when operating the diode at a bias of Vapd=350 V. This is the first time silicon avalanche photo-diodes are employed to measure electrons with Ee