Neutrino oscillation studies with reactors

The observation of neutrino oscillations indicates that neutrinos have mass and that their flavours are quantum mechanical mixtures. Here, the authors review the past, present and future contributions of nuclear reactor-based neutrino oscillation experiments, their accomplishments and the remaining challenges. Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactors have played a major role in the study of neutrino oscillations, a phenomenon that indicates that neutrinos have mass and that neutrino flavours are quantum mechanical mixtures. Over the past several decades, reactors were used in the discovery of neutrinos, were crucial in solving the solar neutrino puzzle, and allowed the determination of the smallest mixing angle θ 13 . In the near future, reactors will help to determine the neutrino mass hierarchy and to solve the puzzling issue of sterile neutrinos.