Setup for irradiation and characterization of materials and Si particle detectors at cryogenic temperatures

A novel facility for proton irradiation with sample cryocooling has been developed at the Accelerator Laboratory of Helsinki University (equipped with a 5 MV tandem accelerator). The setup enables unique experiments to be carried out within the temperature range of 10–300 K. The setup has been constructed for “on-line” studies of vacancies with positron annihilation spectroscopy (PAS) including the option for optical ionization of the vacancies, and for current–voltage (IV) measurements of irradiated silicon particle detectors. The setup is described in detail and typical performance characteristics are provided. The facility functionality was tested by performing PAS experiments with high-resistivity silicon and by IV measurements for two types of irradiated silicon particle detectors.