Pseudocyclic activation analysis of geological material

A pseudocyclic activation system has been installed at the Ecole Polytechnique SLOWPOKE reactor. It is shown that, for analyses of geological material with short-lived nuclides, pseudocyclic activation is preferable to cyclic activation because it avoids the buildup of²⁸Al activity. The total experiment time is reasonable when several sample are analyzed. The possibilities of the technique were illustrated with the analysis of nine well-known silicate rocks. With n cycles an improvement in precision approaching n^1/2 was achieved. The detection limits in silicate rocks were determined for 18 elements using thermal and epithermal irradiation and 25 cycles.