Modifications of natural minerals by irradiation with relativistic heavy ions with and without external pressure

Irradiations with swift heavy ions have been performed using different crystalline target materials and various pressure and irradiation conditions. Changes in the crystal lattice, e.g. the production of point defects and amorphisation, have been characterised by Raman spectroscopy. The cordierite lattice is very resistant against radiation-induced damage, while the amount of volatile phases in the structural channels is significantly changed. Furthermore, a direct conversion from CO2 to CO could be evidenced. Irradiations along the different crystallographic axes did not yield sytematic differences regarding the monitored parameters. In contrast to cordierite, apatite is substantially more sensitive to radiation damage. With increasing fluence, the overall amount of amorphisation increases. However, even for the highest fluences, complete amorphisation could not be achieved. Irradiations along the different crystallographic axes show larger amounts of damage for samples irradiated parallel (0001). The application of external pressure during irradiation stabilises the lattice and can prevent amorphisation. The suitability of large-volume Paris-Edinburgh presses for in-situ irradiation with swift heavy ions could be proven