Description
The Daya Bay nuclear power facility consists of six 2.9GW$_{th}$ pressurized water reactors.The main fission isotopes of these reactors are $^{235}$U, $^{239}$Pu, $^{241}$Pu, and $^{238}$U. The antineutrinos coming from the fissions of these four isotopes are detected with eight functionally identical antineutrino detectors by the Daya Bay experiment. Using the information provided by the power plant, we can track changes in reactor thermal power and fuel composition. From December 2011 to August 2017, we have collected nearly 4 million reactor antineutrino candidates via the inverse beta decay reaction over 1958 days of data collection. The dominant antineutrino detection uncertainty on the neutron detection efficiency is reduced by 56% through a comprehensive neutron calibration and detailed data and simulation analysis. The improved systematic uncertainties and statistics allow us to make a better measurement of the reactor antineutrino flux and energy spectrum as a function of reactor fuel evolution and refined study of the reactor antineutrino anomaly and the 5 MeV bump in the energy spectrum. The results of these improved measurements will be presented in this poster.
| Collaboration | Daya Bay Collaboration |
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