Measurement of k 0 and Q 0 values for iridium isotopes

There is an increasing demand for the chemical analysis of new materials containing iridium. The k ₀-method is an excellent method for the analysis of new materials but measured k ₀-values and Q ₀-values have been lacking for ¹⁹¹Ir(n,γ)¹⁹²Ir, which offers greater sensitivity than ¹⁹³Ir(n,γ)¹⁹⁴Ir. In this work, the Q ₀-values were determined for the two reactions by the two-channel method, using five irradiation channels in two research reactors in Belgium and Canada. These measured Q ₀-values enabled the first determination of the resonance neutron Cd transmission factors for these two capture reactions, confirming suspicions that they are much less than unity. At the two laboratories, k ₀-values were measured for ¹⁹²Ir and ¹⁹⁴Ir and there was good agreement between the two laboratories. The k ₀-values for ¹⁹²Ir are original measurements, while those for ¹⁹⁴Ir are in good agreement with previously published values.