Orateur
Description
Accurate nuclear data are essential for the design and safety optimization of nuclear reactors, as uncertainties directly impact key reactor parameters. In particular, the 19F(n,a)16N reaction is of great interest for fluorine-based molten salt reactors. However, experimental data for the (n,a) channel remain scarce, with cross sections discrepant by up to a factor of three measured from the reaction threshold up to 20 MeV, leading to significant uncertainty propagation on the neutron multiplication factor $k_{eff}$, up to 140 pcm (1 pcm = $10^{-5}$).
We report on a new 19F(n,a)16N cross section measurement performed with the SCALP detector developed at LPC Caen. SCALP consists of a scintillating ionization chamber, operated as a gaseous active target, for the identification of (n,a) reaction channels. Four Photo-Multiplier Tubes surrounding the chamber detect scintillation light produced by particle interactions in the gas for precise neutron kinetic energy determination through time-of-flight measurements. The experiment was carried out at the Neutrons For Science (NFS) facility (GANIL-SPIRAL2, Caen, France), using a pulsed neutron beam with a continuous energy distribution between 1 and 40 MeV.
Preliminary results on the energy-differential 19F(n,a)16N cross section are presented. Data analysis is currently ongoing, and first results will be compared to existing experimental data as well as theoretical evaluations.