ko-factors of 35 isotopes used in reactor neutron activation analysis were measured with a high degree of accuracy (1–2%). To
minimize systematic errors, measurements were carried out using different reactor types, irradiation conditions (18 < Φs/Φe), Ge(Li) detectors, sample detector geometry, etc. Analyst-oriented tabulations including all necessary nuclear data, “best
values”, as well as recommended ko-values are given to facilitate analytical work with the new method. Some practical aspects as well as limitations of the
ko-method are also outlined together with the applied neutron flux and cross-section conventions.