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 <300 ps and with lateral spatial resolution of 30-100 mu m. A counting rate of the gamma-ray to measure positron lifetime is about 10(3) s(-1) which is 10 times higher than that achieved by the radioisotope based microbeam. (C) 2009 Elsevier Ltd. All rights reserved.