Alpha particle emission from reference glass surfaces implanted with Po-210

Implanted long-lived radon decay products in glass surfaces have been used as a measure of past radon exposure in homes. Special track-etch devices (s o-called 'retro-detectors') attached to the glass surface, have the ability to specifically measure the implanted activity of Po-210 in situ. Calibrat ing these devices for Po-210 is fairly straightforward, but the retro-detec tors are also sensitive to the background activity of the glass substrate. Thus, for the successful calibration of retro-detectors, it is necessary to determine the complete alpha emission energy spectrum of the reference gla ss sheet utilised as a calibration pad. In order to achieve accurate knowle dge of the alpha surface emission rate, we have combined several different approaches, i.e. alpha spectrometry of the pad surface with both surface-ba rrier and pulse-ionisation detectors, and activity determination of the gla ss matrix by means of radiochemical methods. The part of the alpha emission spectrum originating from the glass volume is then calculated theoreticall y and compared with experimental results. (C) 2001 Elsevier Science B.V. Al l rights reserved.