COMPARISON OF NAA METHODS TO DETERMINE MEDIUM-LIVED RADIONUCLIDES IN NIST SOIL STANDARD REFERENCE MATERIALS

摘要: In order to determine the elemental concentrations of three new soil standard reference materials SRMs 2709, 2710 and 2711 from National Institute Standards Technology (NIST), a comparative study different medium-lived neutron activation analysis methods was carefully performed. Three irradiation conditions (1-hour thermal, 1-hour epithermal 5-minute epithermal) two counting modes (normal Compton suppression) have been evaluated for following ten elements: As, Au, Cd, Ga, K, La, Mo, Sb, Sm, W. The results show that method 1-day decay is optimum way analyze while addition suppression very beneficial determination K. Using system in conjunction with 1-week decay, ideal Mo W, routine thermal adequate Sm La found soil.