We report a procedure to implant high dose of xenon atoms (Xe) in amorphous carbon, a-C, and amorphous silicon, a-Si, for application in brachytherapy seeds. An ion beam assisted deposition (IBAD) system was used for the deposition of the films, where one ion gun was used for sputtering a carbon (or silicon) target, while the other ion gun was used to simultaneously bombard the growing film with a beam of xenon ion Xe+ in the 0-300 eV range. Xe atoms were implanted into the film with concentration up to 5.5 at.%, obtained with Xe bombardment energy in the 50-150 eV range. X-ray absorption spectroscopy was used to investigate the local arrangement of the implanted Xe atoms through the Xe L-III absorption edge (4.75 keV). It was observed that Xe atoms tend to agglomerate in nanoclusters in a-C and are dispersed in a-Si. (c) 2013 Elsevier B.V. All rights reserved.