Yamada T, Kawada Y, Sato Y, Yunoki A, Hino Y
Japan Radioisotope Association, Tokyo 113-8941, Japan.
Appl Radiat Isot. 2008 Jun-Jul;66(6-7):909-13. doi: 10.1016/j.apradiso.2008.02.073. Epub 2008 Feb 21.
Alpha 4pi(beta+gamma) integral counting technique using a 4pibeta-4pigamma detector configuration was adopted for the standardization of (18)F. In this technique, the beta-detector is composed of two thin plastic scintillators sandwiching the source, coupled with a slender photomultiplier tube. The beta-detector part with the source was inserted into a large well-type NaI(Tl) scintillation detector for gamma-ray detection, making a 4pibeta-4pigamma coincidence counting system. In this work, positron particles were detected with high efficiency in the beta-channel and annihilation quanta were also detected with high efficiency in the 4pigamma channel. The very small inefficiency of the 4pi(beta+gamma) integral counter for the beta-plus branch has been confirmed by EGS5 Monte Carlo simulation. The result using this technique agreed within the uncertainties with the result obtained by the conventional 4pibeta-gamma coincidence counting with the efficiency extrapolation technique using the same detector configuration and a conventional 4pibeta-gamma coincidence counter.
