Graphite has been the first material ever studied by µSR, but a comprehensive scheme to understand its behaviour still lacks. In particular it is not properly known if and how various types of defects in graphite can trap implanted muons. We hence intend to propose a continuation of the experiment RB820359 to probe the muons behaviour when a specific type of defects (in-plane vacancies) is induced in pure graphite (ZYA-HOPG grade). This can be obtained in a controlled way by high-energy (2 MeV) neutron irradiation. Comparison between the obtained results and the effects we have already observed in mechanically-induced defective graphite will allow us to attribute the observed muon relaxation to specific defective sites of graphene structure.