THERMAL EFFECTS PRODUCED AT CRYOGENIC TEMPERATURES IN MATERIALS USED AS BOLOMETRIC DETECTORS FOR DARK MATTER

In the modern cryogenic technique the heat deposited as phonons, the ionization and/or light from scintillation signals could be used for detection. Also, the formation of defects in the lattice structure of material is possible. In the case when the ionization signal is used for detection, a bias voltage must be applied and thus the generalised Luke-Neganov effect must be considered with contributions from the energy stored in the semiconductor lattice as stable defects in the form of Frenkel pairs. In the process of interaction between the projectile particle and the target, the transient phenomena by which the energy is transferred producing ionization, heat and defects was investigated in the frame of a thermal spike model. A detailed discussion of the associated difficulties of this analysis is done and the results put in evidence the interplay between the primary energies deposited in the electronic and lattice subsystems. This process affects the effective number of defects and the energy stored, which is taken into consideration in the balance of energy conservation in Luke Neganov effect