Kinetics of current outflow from electron-hole plasma generated in silicon detectors by relativistic heavy ions

The investigation is focused on the processes associated with the detection of heavy ions of hundreds GeV energy in silicon p⁺-n-n⁺ detectors. In the study, the 1D simulation of the electric field and free carrier density evolution in the ²³⁸U ion track during the first nanosecond was carried out, which demonstrated the initial appearance of narrow high electric field regions adjacent to the contacts and a strong reduction of the electric field in between. The kinetics of the electron-hole plasma dispersal was assigned to a track polarization within 100 ps followed by a delayed track destruction up to its disappearance. It was shown that the process at the p+ contact was governed by the drift of electrons as a merged fraction of free carriers, which controls the hole current flowing between the track and the p⁺ contact. The density of the current initiated by the track polarization was evaluated as 8·10³ A/cm².