NFS
High precision neutron monitor
This new project aims to provide a high precision neutron monitor on the NFS line of the SPIRAL-2 facility at GANIL. NFS is the first operational facility of SPIRAL-2. It will provide neutron beams between 1 and 40 MeV with unmatched intensities. These beams are produced with the proton and deuteron beams accelerated by the SPIRAL-2 facility (GANIL, France).
It is essential that NFS be equipped with a device to measure the flux and energy spectrum of the produced neutrons. The high precision monitor, which is the subject of this new project developed jointly by GANIL and LPC Caen, is a recoil proton spectrometer composed of :
a (n, p) converter: usually a hydrogen-rich material,
a telescope composed of several silicon detectors allowing the measurement of the energy and the identification of the recoil proton.
The use of a hydrogen-rich converter will allow the use of (n, p) scattering, a standard in nuclear data, for the measurement of neutron flux which is essential in the process of normalizing cross sections. It will allow the measurement of cross sections with an accuracy better than one percent. Some of the measurements listed in the “HRPL” published by the NEA could then be made with the required uncertainties. These measurements are of interest for power reactors. Indeed, the improvement of data uncertainties is one of the key parameters to optimize the operation and design of nuclear power reactors in terms of safety and efficiency.
