Gomes R S, Delgado J U, da Silva C J, da Silva R L, da Cruz P A L, Ferreira Filho A L, de Almeida M C M, Iwahara A, de Oliveira A E, Tauhata L
Laboratório Nacional de Metrologia Das Radiações Ionizantes (LNMRI/IRD/CNEN), Av. Salvador Allende, 3773, Barra da Tijuca, CEP 22783-127, Rio de Janeiro, Brazil.
Laboratório Nacional de Metrologia Das Radiações Ionizantes (LNMRI/IRD/CNEN), Av. Salvador Allende, 3773, Barra da Tijuca, CEP 22783-127, Rio de Janeiro, Brazil.
Appl Radiat Isot. 2020 Dec;166:109323. doi: 10.1016/j.apradiso.2020.109323. Epub 2020 Jul 22.
There are few long-lived radionuclides yielding high intensity gamma-rays emission with energies ranging from 100 keV to 500 keV that can be applied as radioactive gamma standard to calibrate HPGe detectors. Furthermore, this energy range represents the main emitted energies of the majority of radionuclides used in nuclear medicine. The Brazilian National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) has attempted to identify radionuclides that have the potential to be used as a calibration source due to their long half-life as well as their emission spectrum. Hence, LNMRI promotes standardization studies of gamma-emitting radionuclides that meet these criteria on order to disseminate them. Thorium-229, with its well-defined energies and relatively high intensities, is one such candidate radionuclide for the energy and full-energy peak efficiency calibration of high-purity gamma spectrometers. Thorium-229 was standardized by the method of 4παβ(LS)-γ(NaI(Tl)) live timed anticoincidence counting. The emission intensities of gamma-rays associated with the decay of Th have been determined by HPGe gamma ray spectrometry with accuracy and precision. The results are in agreement with current literature data.
能够产生能量范围在100千电子伏特至500千电子伏特之间高强度伽马射线发射的长寿命放射性核素很少，而这些放射性核素可作为放射性伽马标准用于校准高纯锗探测器。此外，这个能量范围代表了核医学中使用的大多数放射性核素的主要发射能量。巴西国家电离辐射计量实验室（LNMRI/IRD/CNEN）已尝试识别因其长半衰期及其发射光谱而有潜力用作校准源的放射性核素。因此，LNMRI推动对符合这些标准的伽马发射放射性核素进行标准化研究以便推广它们。钍-229具有明确的能量和相对较高的强度，是用于高纯伽马光谱仪能量和全能峰效率校准的此类候选放射性核素之一。钍-229通过4παβ(LS)-γ(NaI(Tl))活时间反符合计数法进行了标准化。与钍衰变相关的伽马射线发射强度已通过高纯锗伽马射线光谱法精确测定。结果与当前文献数据一致。
