Grigorescu E L, Negut C D, Luca A, Razdolescu Anamaria Cristina, Tanase Mioara
National Institute of R&D for Physics and Nuclear Engineering Horia Hulubei- IFIN-HH, Atomistilor str. 407, POB MG-6, Bucharest-Magurele 76900, Romania.
Appl Radiat Isot. 2004 Feb-Apr;60(2-4):429-31. doi: 10.1016/j.apradiso.2003.11.054.
The radionuclide 68Ga is mainly a positron emitter (89.2%), with a half-life of 67.7 min. It is used in nuclear medicine, being chemically extracted from the mixture 68(Ge+Ga); its precursor, 68Ge, disintegrates 100% by electron capture, with a half-life of 270.8d (Table of radionuclides, comments and Evaluation). A 4pibeta-gamma coincidence method was used for standardization, with a 4pi proportional beta-detector and a NaI(Tl) gamma detector. Registration of the capture radiations was avoided using foil absorption and a high beta threshold. Using supplementary foils for positron absorption, extrapolation graphs were obtained, with a mean slope of -4.4%. Care was taken to compensate for the loss of 68Ge during the preparation of solid sources for measurement. A combined uncertainty of 1.1% was estimated.
