Investigations into properties of charge traps created in CCDs by neutron and electron irradiation

摘要

Our group has been investigating the effects related to radiation damage of CCDs since 1998. In a series of measurements in 2003 we found the puzzling effect of very slow filling of charge traps created by radiation damage of the silicon device. In 2005 we intended to study this phenomenon in detail. However, while in 2003 we could see all the traps created by neutron irradiation in 1998–1997 unchanged, such traps unexpectedly almost completely disappeared in 2005. We explain this as an effect of annealing induced by electron irradiation, as in 2003 we irradiated with electrons the same device irradiated with neutrons in 1997–1998. Results of the 2005 measurements are presented.