Ashenfelter, J.Balantekin, A. B.Baldenegro, C.Band, H. R.Bass, C. D.Bergeron, D. E.Berish, D.Bignell, L. J.Bowden, N. S.Boyle, J.Bricco, J.Brodsky, J. P.Bryan, C. D.Bykadorova Telles, A.Cherwinka, J. J.Classen, T.Commeford, K.Conant, A.Cox, A. A.Davee, D.Dean, D.Deichert, G.Diwan, M. V.Dolinski, M. J.Erickson, A.Febbraro, M.Foust, B. T.Gaison, J. K.Galindo-Uribarri, A.Gilbert, C.Gilje, K.Glenn, A.Goddard, B. W.Hackett, B.Han, K.Hans, S.Hansell, A. B.Heeger, K. M.Heffron, B.Insler, J.Jaffe, D. E.Ji, X.Jones, D. C.Koehler, K.Kyzylova, O.Lane, C. E.Langford, T. J.LaRosa, J.Littlejohn, B. R.Lopez, F.Lu, X.Martinez Caicedo, D. A.Matta, J. T.McKeown, R. D.Mendenhall, M.Miller, H. J.Minock, J.Mueller, P. E.Mumm, H. P.Napolitano, J.Neilson, R.Nikkel, J. A.Norcini, D.Nour, S.Pushin, Dimitry A.Qian, X.Romero-Romero, E.Rosero, R.Sarenac, DusanSeilhan, B.Sharma, R.Surukuchi, P. T.Trinh, C.Tyra, M. A.Varner, R. L.Viren, B.Wagner, J. M.Wang, W.White, B.White, C.Wilhelmi, J.Wise, T.Yao, H.Yeh, M.Yen, Y.-R.Zhang, A.Zhang, C.Zhang, X.Zhao, M.2019-07-302019-07-302019-04-01https://doi.org/10.1016/j.nima.2018.12.079http://hdl.handle.net/10012/14827The final publication is available at Elsevier via https://doi.org/10.1016/j.nima.2018.12.079 © 2018 This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/ licenses/by-nc-nd/4.0/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 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 7 m to 13 m from the High Flux Isotope Reactor core. It will probe the best-fit point of the ¯ve disappearance experiments at 4σ in 1 year and the favored regions of the sterile neutrino parameter space at more 3σ than in 3 years. PROSPECT will test the origin of spectral deviations observed in recent θ13 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.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalneutrino oscillationneutrino mixingreactorPROSPECTArticle