Positron lifetime spectrometer for metal studies

The instrument to be described is of the fast-slow coincidence type based on the well known time-to-amplitude conversion principle. Simplicity in circuit design has been achieved by using IC components. Special attention has been paid to the fast response and the temperature stability of the instrument. This fast reponse allows the omission of the pile-up limiter circuits. The temperature stability is adequate (5 psec/°C) for measurements to be made under normal laboratory conditions. Positron lifetimes were measured in both annealed and deformed copper.