A positron annihilation lifetime measurement system with an intense positron microbeam

Abstract: An intense positron microbeam was formed using an electron linear accelerator. The beam is pulsed to apply positron lifetime spectroscopy to very small samples and to obtain positron lifetime images by scanning it. Positron lifetimes are measured with time resolution of <300ps and with lateral spatial resolution of 30–100μm. A counting rate of the γ-ray to measure positron lifetime is about 103 s−1 which is 10 times higher than that achieved by the radioisotope based microbeam. [Copyright &y& Elsevier]