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- Author or Editor: B. De Wet x
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Abstract
A major matrix effect that hampers nuclear analysis with charged particles is found in the range differences which charged particles experience in samples and comparators. The determination of lithium in ores was attempted by the previous determination of the ranges of protons therein. This was achieved by the homogeneous spiking of the ores with pure boron compounds of known composition and therefore known calculated ranges. Pure lithium compounds, also with known calculated ranges, were used as lithium standards. Determinations were carried out by proton-induced prompt photon spectrometry on nuclides of lithium and boron. Results obtained for standard reference ores, SRM 181 and-183, were in good agreement with the specificfied values.
Abstract
The prompt gamma-rays 1219-keV35Cl p/1, O/ and the 1763-keV35Cl p/2, O/ induced by 5 MeV protons were measured during irradiation of 15 pure chlorine compounds of known composition. Stopping powers of target materials were calculated from tables and the use of the Bragg-Kleeman rule. Apparent discrepancies in the measured yields could point to deviations from the Bragg-Kleeman rule and hence to molecular effects. The value of any molecular effects was found to be 
7.9%.
Abstract
The determination of sulphur through 
-ray spectrometry induced by 5 MeV protons was chosen to study the effect of dilution and spike addition on the stopping power of the matrix and applied to the determination of sulphur in coal. Changes in the matrix cannot be ignored even for the spiking technique.
