2006 CTBT Intercomparison of Atmospheric Particle Filter Sample

The paper describes the whole progress of 2006 proficiency test exercise organized by the Comprehensive Nuclear-Test-Ban Treaty organization (CTBTO). The atmospheric particle filter samples were measured by HPGe detector (relative detective efficiency is 76%), all the major radio-nuclides in reference sample were identified, and their activities and activity concentrations were calculated accurately. The zero time determined by the 95Nb and 95Zr activity ratio is in agreement with the reference value, the deviation is only 0.57 days.