Evaluation of radiation-damage halos in quartz by cathodoluminescence as a geochronological tool

Detailed quantitative cathodoluminescence (CL) imaging analysis was carried out for radiation-damage halos observed by CL (CL halo) created in natural quartz by implantation of 4 MeV He+ ions. The band of CL halo was approximately 14 μm in width and was constant for any He+ ion dose. The width of the halo is consistent with the theoretical range of 4He ions in quartz. A quantitative response of CL intensity to He+ ion dose was obtained, leading to the application of CL halos to geodosimetrical use. The CL intensity increases exponentially in the luminescent band from the implantation surface to the inside, until it reaches a maximum at 14 μm depth, with a rapid decrease beyond this point. This result is as predicted by Bragg's law, although we find some differences between the CL intensity and the theoretical stopping power.