Standardization of 68(Ge+Ga).
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.
National Institute of R&D for Physics and Nuclear Engineering Horia Hulubei- IFIN-HH, Atomistilor str. 407, POB MG-6, Bucharest-Magurele 76900, Romania. elgrigorescu@yahoo.com
E L
EL
Grigorescu
C D
CD
Negut
A
A
Luca
Anamaria Cristina
AC
Razdolescu
Mioara
M
Tanase
D000465:Algorithms; D045424:Complex Mixtures / Q000032:analysis / Q000592:standards; D005710:Gallium Radioisotopes / Q000032:analysis* / Q000592:standards*; D005720:Gamma Rays; D005857:Germanium / Q000032:analysis* / Q000592:standards*; D006207:Half-Life; D011868:Radioisotopes / Q000032:analysis / Q000592:standards; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013051:Spectrometry, Gamma / Q000379:methods* / Q000592:standards*
D045424:Complex Mixtures; D005710:Gallium Radioisotopes; D011868:Radioisotopes; D005857:Germanium