Digital triple coincidence positron lifetime setup with DRS4 and its benefits

A triple coincidence digital positron lifetime setup is commonly used in the laboratory of the positron annihilation spectroscopy at the Slovak Technical University for more than ten years. During its operation, several changes and upgrades were accomplished. With the process being carried out, enhancement of the timing resolution and reduction of the setup complexity were achieved. Requirements of other laboratories, like automatic time measurement, were included in the QtPALS software developed at the institute of nuclear and physical engineering in Bratislava. Benefits of triple coincidence, commonly used in positron annihilation spectra background suppression in samples containing 60Co, are also in better time resolution, which outbalanced increasing of the measurement time. Used custom FPGA firmware in DRS4 evaluation board from Paul Scherrer Institute allows use of the digital positron lifetime setup without external coincidence trigger chain.