TECHNIQUE FOR EVALUATION OF SYSTEMATIC ERRORS IN ACTIVATION ANALYSIS FOR OXYGEN WITH 14-MEV NEUTRONS

In comparative 14-MeV neutron activation analysis of oxygen, the neutron and gamma ray attenuation differences in the sample and standard introduce systematic errors. A quantitative evaluation of these attenuation processes in a wide range of matrices and for three sample diameters is given. The experimentally determined correction factor, in each case, shows an exponential dependence on the calculated difference between the appropriate attenuation coefficients for sample and standard. Within the range of sample diameters tested, preliminary data indicate that the slope of each calibration line is linearly dependent on the sample diameter. For comparable diameters, the magnitude of the slope for neutron attenuation is approximately ten times greater than for gamma attenuation. These calibration lines are used to predict attenuation correction factors for the determination of oxygen in other matrices. Some typical analyses of Standard Reference Materials, corrected for attenuation, illustrate the high degree of accuracy and precision obtained. © 1968, American Chemical Society. All rights reserved.