An all-digital time differential γ-γ angular correlation spectrometer for the study of defects in semiconductors

The time differential perturbed angular correlation (PAC) technique permits the analysis of electric field gradients and magnetic fields at sites of radioactive probe atoms inserted into samples by means of implantation or diffusion. In this work a new all-digital PAC spectrometer is presented which overcomes some ot the limitations of earlier digital and analog setups and features improved time and energy resolutions. The application of the new spectrometer for the characterization of defects in semiconductors using isotopes that could not be efficiently used as probes before is discussed. Other possible applications of the methods developed for the spectrometer include positron annihilation, PET and time of flight studies as well as Lidar and Radar.