The PROSPECT Reactor Antineutrino Experiment

The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make both a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and to probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long baselines. PROSPECT utilizes a segmented $^6$Li-doped liquid scintillator detector for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT is a movable 4-ton antineutrino detector covering distances of 7m to 13m from the High Flux Isotope Reactor core. It will probe the best-fit point of the $\bar\nu_e$ disappearance experiments at 4$\sigma$ in 1 year and the favored regions of the sterile neutrino parameter space at more than 3$\sigma$ in 3 years. PROSPECT will test the origin of spectral deviations observed in recent $\theta_{13}$ experiments, search for sterile neutrinos, and address the hypothesis of sterile neutrinos as an explanation of the reactor anomaly. This paper describes the design, construction, and commissioning of PROSPECT and reports first data characterizing the performance of the PROSPECT antineutrino detector.Comment: 30 pages, 33 figures; updated with journal revision and referenc

The Agricultural Productivity of Chaco Canyon and the Source(s) of Pre-Hispanic Maize Found in Pueblo Bonito

Agricultural productivity estimates suggest that the core area of Chaco Canyon could have sustained only a few hundred individuals. Modern analogues of existing Pueblo populations and their domestic habitations with Chaco structures suggest that Chaco at times had a resident population exceeding 2000 people. These data suggest that maize would have had to be imported to feed permanent residents and those visiting Chaco during ritual–political gatherings and those who participated in the accelerated construction and modification of great houses between AD 1030 and 1130. Comparison of strontium-isotope and trace-element ratios of synthetic soil and natural waters from sites within the San Juan Basin of northwestern New Mexico with isotopic and trace-element ratios of seven archaeological corn cobs found in Pueblo Bonito indicate that some maize was imported from either the Newcomb area or from side-tributary sites west of the Chaco Canyon core. These data support the concept that foodstuffs (maize) from outlier communities were transported to a resource-poor Chaco Canyon. However, proof that importation of maize was the rule and not the exception awaits further study of archaeological cobs from both small-house and great-house contexts