PROSPECT-II calibration strategy

The PROSPECT experiment completed its first data-taking run by the end of 2018 and reported high precision electron-antineutrino spectra and oscillation results at a short baseline about $\sim$ 7m from the highly-enriched $^{235}$U reactor core at High Flux Isotope Reactor(HFIR). For the second run an upgraded detector PROSPECT-II aims to further reduce $^{235}$U spectrum uncertainty and expand the oscillation sensitivity in the high mass-splitting regime. The upgrades include modifications to the containment vessel, inner detector, and calibration system to minimize dead mass inside the detector and materials in contact with the liquid scintillator. In this talk, I will describe the PROSPECT-II calibration system and its expected performance, based on PROSPECT-I data and Monte Carlo simulations.