First Observation of Coherent Elastic Neutrino-Nucleus Scattering

Description

This thesis describes the experimental work that finally led to a successful measurement of coherent elastic neutrino-nucleus scattering—a process proposed forty-three years ago. The experiment was performed at the Spallation Neutron Source facility, sited at Oak Ridge National Laboratory, in Tennessee. Of all known particles, neutrinos distinguish themselves for being the hardest to detect, typically requiring large multi-ton devices for the job. The process measured here involves the difficult detection of very weak signals arising from nuclear recoils (tiny neutrino-induced “kicks” to atomic nuclei), but leads to a much larger probability of neutrino interaction when compared to all other known mechanisms. As a result of this, “neutrino technologies” using miniaturized detectors (the author's was handheld and weighed only 14 kg) become a possibility. A large community of researchers plans to continue studying this process, facilitating an exploration of fundamental neutrino properties that is presently beyond the sensitivity of other methods. Front Matter ....Pages i-xiv Introduction (Bjorn Scholz)....Pages 1-8 Coherent Elastic Neutrino–Nucleus Scattering (Bjorn Scholz)....Pages 9-13 COHERENT at the Spallation Neutron Source (Bjorn Scholz)....Pages 15-20 Background Studies (Bjorn Scholz)....Pages 21-28 The CsI[Na] CEνNS Search Detector at the SNS (Bjorn Scholz)....Pages 29-41 Light Yield and Light Collection Uniformity (Bjorn Scholz)....Pages 43-56 Barium Calibration of the CEνNS Detector (Bjorn Scholz)....Pages 57-79 Measurement of the Low-Energy Quenching Factor in CsI[Na] (Bjorn Scholz)....Pages 81-104 CEνNS Search at the SNS (Bjorn Scholz)....Pages 105-141 Conclusion (Bjorn Scholz)....Pages 143-144