Digitized positron lifetime spectrometer for the simultaneous recording of time and energy information

Positron annihilation (PA) techniques became, by now, routinely used nuclear techniques with applications which range from structural investigations of materials to biological samples and medical applications in positron emission tomography (PET). As at present, both PA spectroscopy and PET could profit from an improvement in the fast coincidence technique, it was investigated how far a fully digitized positron lifetime spectrometer (with full event storage capability for the simultaneous recording of time and energy information of the γ-rays) could offer advantages over a conventional setup employing fast analogue nuclear electronics. The additional information allows off-line analysis which could be particularly useful in separating various annihilation channels, like the positronium contribution, recently recognized to offer a new 'window of observation'