Fig. (10) XPS data for the Be mirror exposed to deuterium plasma ions: ♦ – Ar+ion cleaning, Ei = 300 eV (X1 in Fig. 9); ● – reflectance drop after D+ ion bombardment, Ei= 1350 eV (X2 in Fig. 9); ■ – reflectance recovery after exposure to D+ions, Ei=60 eV, after the second reflectance drop (X3 in Fig. 9) [43].