Operation of a 3He proportional counter in the Ganymede radiation environment

► Proposed radiation tolerant neutron spectrometer for the Jupiter Ganymede Orbiter. ► Simulations of background in 3He neutron detectors from charged particle radiation. ► Simulation benchmarking using data from the Lunar Prospector Neutron Spectrometer. ► Simulation of the response of these detectors to the radiation environment around Ganymede. ► Demonstration of the capabilities of a neutron spectrometer to map water-ice on Ganymede.