  We present the first Fermi - Large Area Telescope (LAT) solar flare catalog
covering the 24 th solar cycle. This catalog contains 45 Fermi -LAT solar
flares (FLSFs) with emission in the gamma-ray energy band (30 MeV - 10 GeV)
detected with a significance greater than 5 sigma over the years 2010-2018. A
subsample containing 37 of these flares exhibit delayed emission beyond the
prompt-impulsive hard X-ray phase with 21 flares showing delayed emission
lasting more than two hours. No prompt-impulsive emission is detected in four
of these flares. We also present in this catalog the observations of GeV
emission from 3 flares originating from Active Regions located behind the limb
(BTL) of the visible solar disk. We report the light curves, spectra, best
proton index and localization (when possible) for all the FLSFs. The gamma-ray
spectra is consistent with the decay of pions produced by >300 MeV protons.
This work contains the largest sample of high-energy gamma-ray flares ever
reported and provides the unique opportunity to perform population studies on
the different phases of the flare and thus allowing to open a new window in
solar physics.
