Determination of Q 0 and k 0 factors for 75Se

Since the initial determination of the Q ₀ and k ₀ factors for ⁷⁵Se systematic errors in Se determination in various matrices have been noticed by several users of the k ₀ method. A number of publications have been made on this subject, resulting in different k ₀ and Q ₀ values for this radio-isotope. This work consists of a re-determination of Q ₀ and k ₀ values for ⁷⁵Se using the bare and Cd-ratio methods making use of three different irradiation channels from the BR1 reactor. For this re-determination three different kinds of standards were used: a pure Se powder standard, an ICP standard solution and pure Se shots. Results were compared with previously published literary data. Differences in k ₀ with the official published data ranging from 3.5 to 12 % were observed and potential reasons for this discrepancy are discussed. A good consistency with recent work was found. The impact on recent certification and intercomparison exercises demonstrates the effectiveness of the newly proposed values.