Based on an idea by Carlo Rubbia, the n_TOF facility has been operating during the last 20 years at CERN. n_TOF is a spallation neutron source, driven by the 20 GeV/c proton beam from the CERN PS accelerator. A massive Lead spallation target is feeding two experimental areas set at 185 meters (EAR1, horizonal with respect to the proton beam direction) and at 20 meters (EAR2, in the vertical direction) from the spallation source. Neutrons in a very wide energy range - from GeV down to sub-eV kinetic energy - are generated and selected by the time-of-flight technique, with the long flight paths ensuring the possibility of performing very high-resolution measurements.
Over the course of two decades, more than one hundred experiments have been performed by the n_TOF Collaboration, in the domain of nuclear data for advanced technologies (neutron capture, neutron induced fission and (n,cp) reactions for accelerator driven systems, Gen-IV and Th/Ufuel cycle), in nuclear astrophysics (synthesis of the heavy elements in stars, big bang nucleosynthesis, nuclear cosmo-chronology), and for basic nuclear science (nuclear structure and decay of highly excited compound states). Overall, measurements at n_TOF generated ~100 entries in the EXFOR database, covering over 90% of the data released by the n_TOF Collaboration.
During the planned shutdown of the CERN accelerator complex, between 2019 and 2021, the facility went through a substantial upgrade with a new target-moderator assembly, refurbishing of the neutron beam lines and experimental areas. An additional station (the NEAR Station) has been set up at approximately 2 m from the target-moderator assembly. The NEAR Station capabilities for performing material irradiation studies, neutron induced activation and new physics opportunities are presently explored.
An overview of the experimental activities performed at n_TOF will be presented, with a particular emphasis on the most recent results and planning for the future.
(*) Spokesperson of the n_TOF Collaboration