[en] Ion implantation and microanalysis have been used to investigate plasma-surface interactions relevant to fusion applications. Previous results for pure metals are reviewed and current results are presented for TiB₂ and B₄C coatings for tokamak surfaces. Enhanced trapping of implanted, low-energy hydrogen has been shown to occur at room temperature in W, Au, Pd, Mo, Nb, TiB₂, and B₄C for He or other ion predamage. Hydrogen depth profiles obtained using ¹H(¹⁹F, αγ)¹⁶O resonant nuclear reaction show that the H decorates the He damage profiles at traps whose concentration is proportional to the amount of He-induced damage