Simultaneous inter-calibration of 160 MiMi neutron detectors

Abstract

The 160 MiMi neutron detectors of SAFFRON, a 3D full-core mapping system developed at EPFL for the CROCUS zero-power reactor, have been simultaneously inter-calibrated in preparation for their in-core installation. An experimental setup was built to distribute up to 180 MiMi detectors radially at 15 cm around the Pu-Be neutron source of the CARROUSEL facility. An efficient inter-calibration methodology is presented: first, the azimuthal shape of the relative source strength is characterized by rotating 18 MiMi detectors distributed every 20º around the PuBe, followed by the simultaneous determination of the relative sensitivity of 160 MiMi detectors, distributed all around the Pu-Be source.