A multi-element serum standard for neutron activation analysis

An annular ²²⁷AcBe isotopic neutron source, containing 6.6-Ci ²²⁷Ac, is described for application in fast and thermal neutron activation analysis, with high accuracy, for major constituents in ores, alloys and industrial concentrates. The characteristics of the neutron output and of the fast, epithermal and thermal flux and flux gradients is described in detail. The determination of manganese in pyrolusite ores and ferro-manganese is compared to results obtained previously with a cylindrical 1-Ci ²²⁶RaBe source. Two new sources of systematic errors have been discovered.