“…The irradiation experiments includes diverse radiation, for instance electromagnetic radiation with short wavelengths like Y-irradiation, [41] X-ray irradiation, [70,71] radiation in the visible optical spectrum, [35,36,44] or radiation with wavelengths in the NIR or IR [72,73] region. In addition scientists carried out particle irradiation using beams consisting of electrons, [42,[74][75][76] ions, [37,74,[77][78][79] protons, [80,81] and neutrons. [75,82] Within the group of particle irradiation experiments the results achieved with oxygen ion bombardment (ion etching) seem to be the most promising ones.…”