Measurement of the Reactor Antineutrino Spectrum of U-235 by PROSPECT and Daya Bay

Since their experimental discovery over 60 years ago, neutrinos have proven to be a fascinating means of exploring the physical universe. Through a variety of both natural and man-made sources, physicists have discovered many unusual features about these par- ticles from their oscillation between their different flavor states to their particularly small mass. There are still many questions to answer regarding these fundamental particles, though. Among these questions is whether a possible fourth type of neutrino exists, a sterile neutrino, which could resolve a range of discrepancies between recent measure- ments and predictions at a variety of different energies and baselines. Precision neutrino measurements may also help to solve questions in nuclear physics and resolve previously measured spectral distortions.The PROSPECT experiment is a 4 ton, 6Li-loaded liquid scintillator detector at Oak Ridge National Laboratory operating \u3c10m from the High Flux Isotope Reactor, a re- search reactor highly enriched in 235U. The segmented design of the detector allows for unprecedented background rejection at the Earth’s surface. Here I will describe the design, construction, data taking, and analysis of PROSPECT towards its measurement of over 50,000 neutrino events and the results from both its sterile neutrino search and its preci- sion measurement of the 235U antineutrino spectrum. Further, I will describe the analysis that combines results from the PROSPECT and Daya Bay 235U measurements and present the most precise measurement of the 235U antineutrino energy spectrum to date