Novel beta-gamma coincidence measurements using phoswich detectors

Summary

We have developed an analysis pipeline for air filter gamma-ray spectra, utilizing the software packages UniSampo for peak analysis and Shaman for nuclide identification. In an automated usage mode, spectra that are received via e-mail are processed into a directory tree, analyzed with UniSampo and Shaman, and finally categorized on the basis of the analysis results. Alarms are generated if anything out of the ordinary is observed. Typical applications for an air filter analysis pipeline are national radioactivity surveillance networks and the global radionuclide monitoring network being implemented for verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Our analysis pipeline system has been used by the Finnish national CTBT-authority, the Finnish National Data Center (FiNDC), since July 1999. Evaluation with a randomly selected set of 1518 air filter spectra showed that our pipeline system produces significantly better analysis results than that utilized by the CTBT Organization (CTBTO): our system found 4.2 more peaks per spectrum than the CTBTO system (9 % increase) and identified 5.6 more peaks per spectrum (14 % increase) on the average.