ABSTRACT
This chapter presents a short introduction to the working principles of a silicon sensor, the signal formation, and the effects of radiation damage. A clear and detailed explanation of the principles of operation of semiconductor sensors, with a specific emphasis on silicon is presented. A charged particle traversing a silicon bulk interacts electromagnetically with the electrons of the atoms, losing energy gradually, and causing two different processes: atomic excitation, displacing electrons to higher atomic orbitals, and ionization, producing electron-ion pairs. The deposited energy is lower because a fraction of the lost energy is carried off by energetic knock-on electrons. Delta rays appear when a particle loses a large amount of its energy during a single interaction, and the electrons produced have enough energy to ionize other atoms. The radiation damage induced in silicon sensors can be classified into two distinct categories: surface damage, due to ionization, and bulk damage, due to the non-ionizing processes.
