Laboratory studies of radiation effects in water ice in the outer solar system

We present new experimental results on radiolysis of water ice below 140 K induced by 150-eV electrons and 100-keV ions, obtained to understand processes occurring in the outer solar system and interstellar space. The experimental methods discussed are low-energy electron-energy-loss spectroscopy (EELS) and Fourier-transform-infrared (FTIR) spectroscopy. The phenomena studied are the formation and trapping of radiation products, in particular H2O2, and radiation-induced amorphization of crystalline ice.