On the sample shape and dimensions for gamma activation analysis

The optimum geometry for irradiating samples and recording induced activity during gamma-activation elemental analysis of rooks and ores is suggested. Using a cylindrical sample, whose diameter would essentially exceed the height, and the cylinder axis during irradiation would be perpendicular to the beam axis, is recommended. In order to provide uniformity of sample activation, the cuvette rotates about its own axis during irradiation. Two scintillation detecting units, the distance between whose crystals equals the cuvette height, are used for recording induced activity. The advantages of the said geometry are noted. Problems of determining optimum sample sizes have been also examined in detail with regard to measurements of gold concentration in samples of gold-containing ores. Activation has been carried out on a high-current electron linear accelerator. An analysis of the obtained results shows the advisability of selecting the following sample sizes: diameter 100 mm and height 40 mm