DAWN GRAND MAP CERES TPE NEUTRON COUNTS V1.0

The map was determined from a time series of the rate of neutron capture by lithium in the lithium-loaded glass scintillator, part of the +Z phoswich sensor on Dawn's Gamma Ray and Neutron Detector (GRaND). Neutrons in the thermal and epithermal energy range contribute to the reaction.

The data were acquired while in low altitude mapping orbit, about 385 km from Ceres' surface (about 0.8 body radii altitude). Prior to mapping, the time series counting data were subjected to corrections for variations in the flux of galactic cosmic rays and measurement geometry, as described by PRETTYMANETAL2017.