Fig. (12) Reflectance of an Al mirror sample at the indicated wavelengths versus the total ion fluence. Sharp falls are the result of short-term bombardment by 1350 eV deuterium plasma ions (stages 1, 2, 4) and with a wide energy distribution (100-1350 eV, stage 3). All rises are due to long-term exposures to low-energy ions (60 eV) [46].