The operation and performance of Current Injected Detector (CID)

Radiation hardness up to 1×1016cm-2 is required in the future high-energy physics experiments. This is well beyond the radiation tolerance of even the most advanced semiconductor detectors fabricated by commonly adopted technologies. The Current Injected Detector (CID) is a device in which the current is limited by the space charge, which originates from injected carriers trapped by the deep levels. This induces a stable electric field through the entire detector bulk regardless of the irradiation fluence the detector has been exposed to. The steady state density of the trapped charge is defined by the balance between the trapping and emission rates of charge carriers (detrapping). Thus, the amount of charge injection needed for electric field stabilization depends on the temperature. The CID mode has a new specific feature which limits the maximum operational voltage. It is connected with the space charge density saturation and the sharp current rising at the threshold voltage VT. The value of VT is proportional to the irradiation fluence and it increases with respect to the irradiation fluence extending the range of the operation voltage.