SFINX: Soviet-French integral experiment on measuring the capture and fission at Masurca and BFS

The SFINX experiment was aimed at the comparison of experimental procedures used at the MASURCA and the BFS critical assemblies for measuring the ratio of the 238U and 239Pu average fission cross-sections to the 235U average cross-section (F8/F5, F9/F5) and of the 238U average capture cross-section to the 239Pu average fission cross section (C8/F9). As part of the calibration of the measurements F8/F5 and F9/F5 were also measured in a thermal column. To obtain C8/F9, absolute measurements of capture rates in 238U and fission rates in 239Pu and 235U were carried out. The measurements were made in September 1987 at the MASURCA facility (FRANCE) in the BALZAC 1 critical assembly and in the thermal column of the HARMONIE facility. In April 1989 these measurements were complemented by joint measurements of the 239Pu absolute fission rate at the BFS 55-1 critical assembly (USSR)