Development of a Low-power, Low-cost, Front-end Electronics Module for Large-Scale Distributed Neutrino Detectors. Final Report

Final technical report for Advanced detector research program award at UCLA. To date, only two objects have been observed using neutrino messengers. However, each observation illustrates the incisive power of neutrino observations for both astrophysics and for particle physics. The first source observed with neutrinos was the Sun by Ray Davis and collaborators using a chlorine nuclear target. Until then, only electromagnetic emissions produced near the surface of the Sun had been studied. With neutrinos, the hydrogen-burning core of the Sun is directly observed - we now know even with its predicted intensity. Because neutrinos are so deeply penetrating, they give a direct window on the most energetic processes in the universe, unobscured by photospheres, fireballs and materials opaque to light. The solar neutrino observations largest impact however was felt by particle physicists. This experiment and follow-up experiments with water, heavy water, and gallium all observed the well-known deficit of the predicted number of electron-type neutrinos. After several decades of research using both astrophysical and accelerator observations inspired by this result, the effect is now known to be due the transformation of electron-type neutrinos into one of the two other flavors of neutrinos. These observations were the first and strongest data that showed particle physicists that the mass (propagating) eigenstates and weak eigenstates of neutrinos and their weak eigenstates are not identical. In addition, this transformation was the first indication that neutrinos have a small, but non-zero mass. The second, and latest, discovery of a cosmic neutrinos source was the explosion of supernova SN1987a in the Large Magellanic Cloud. In a type IIa supernova, 99% of the energy is expected to be released in the form of neutrinos since no other energy could escape the dense environment. The observations of SN1987a confirmed the theoretical models of this type of stellar core collapse, again only possible since neutrinos are so deeply penetrating they yield a direct window on the astrophysical processes. The observation again yielded significant impact on particle physics. The lack of dispersion of neutrino arrival times yielded the strongest upper bound on neutrino mass, only recently conclusively surpassed by laboratory tests. These few events still yield the strongest constraints on neutrino decay scenarios for the so-called 'normal' neutrino mass hierarchy.