"Dip-sticks" calibration handles self-attenuation and coincidence effects in large-volume gamma-ray spectrometry

Routine gamma-spectrometric analyses of samples with low-level activities ( e.g. food, water, environmental and industrial samples) are often performed in large samples, placed close to the detector. In these geometries, detec tion sensitivity is improved but large errors are introduced due to self-at tenuation and coincidence summing. Current approaches to these problems com prise computational methods and spiked standard materials. However, the fir st are often regarded as too complex for practical routine use, the latter never fully match real samples. In the present study, we introduce a dip-st icks calibration as a fast and easy practical solution to this quantificati on problem in a routine analytical setting. In the proposed set-up, calibra tions are performed within the sample itself, thus making it a broadly acce ssible matching-reference approach, which is principally usable for all sam ple matrices. (C) 2000 Elsevier Science B.V. All rights reserved.