Speaker
Vladimir Eremin
(Ioffe Physical Technical Institute)
Description
The recent study of silicon detectors irradiated up to fluences beyond 10^15 neutron/cm^2 demonstrated an increase of the collected charge up to the value that is even higher than the charge initially generated by the detected particles. In the present investigation this effect is analyzed in terms of avalanche process in the abrupt p-n junctions. On the basis of double peak electric field distribution model developed earlier in the Ioffe institute, the dependence of the detector signal is calculated for different fluences and the detector operational bias. It is shown that the electric field distribution in heavy irradiated detectors is close or corresponds to the requirements for the avalanche process. In the case of short range particles the effect is more pronounced and can be observed. For MIPs detection it is suppressed by the spreading of generated pairs along the detector thickness ant therefore it requires higher bias voltage. The detector parameters which allow reaching an evident avalanche effect are defined and discussed in terms of detector operational environment and biasing conditions.
Author
Vladimir Eremin
(Ioffe Physical Technical Institute)
Co-authors
Dr
Elena Verbitskaya
(Ioffe Physical Technical Institute)
Jaakko Härkönen
(Helsinki Institute of Physics, CERN/PH)
Dr
Zheng Li
(Brookhaven National Laboratory)
