Activity measurements of ~(3)H using the TDCR method and observation of source stability

摘要

Activity measurements of ~(3)H were performed using the triple to double coincidence ratio method for the 2009 international comparison organized by the Bureau International des Poids et Mesures (BIPM). The activity obtained by using the FPGA (field programmable gate array) acquisition system and software event analysis was compared to that using MAC3 (Module d'Acquisition de Coincidences triples). Agreement to better than 0.4percent was obtained. The stability of sources prepared in Ultima Gold~(TM), Ultima Gold~(TM) LLT, Insta-Gel~(R) Plus and Optiphase "Hisafe"-3 over 140 days is presented.