Title: Measuring High-Energy Spectra with HAWC,
Abstract: The High-Altitude Water-Cherenkov (HAWC) experiment is a TeV $\gamma$-ray
observatory located \unit[4100]{m} above sea level on the Sierra Negra mountain
in Puebla, Mexico. The detector consists of 300 water-filled tanks, each
instrumented with 4 photomultiplier tubes that utilize the water-Cherenkov
technique to detect atmospheric air showers produced by cosmic $\gamma$ rays.
Construction of HAWC was completed in March of 2015. The experiment's wide
instantaneous field of view (\unit[2]{sr}) and high duty cycle (> 95\%) make it
a powerful survey instrument sensitive to pulsars, supernova remnants, and
other $\gamma$-ray sources. The mechanisms of particle acceleration at these
sources can be studied by analyzing their high-energy spectra. To this end, we
have developed an event-by-event energy-reconstruction algorithm using an
artificial neural network to estimate energies of primary $\gamma$ rays at
HAWC. We will present the details of this technique and its performance as well
as the current progress toward using it to measure energy spectra of
$\gamma$-ray sources.