FORMATION OF THE (ARC60)-AR-41 ENDOHEDRAL COMPLEX BY PROMPT NUCLEAR RECOILING FOLLOWING NEUTRON-IRRADIATION

It is demonstrated that by the neutron irradiation of polycrystalline C-60 in an argon gas atmosphere or of C-60 crystals containing previou sly ab- and adsorbed argon, a stable endohedral argon compound is form ed. The concentration of argon has been determined by instrumental neu tron activation analysis (INAA) via the short-lived Ar-41 isotope. It is supposed that the endohedral compound is formed by the penetration of the argon atom into the C-60 cages; a mechanism due to the high kin etic energy recoiling Ar-41 atoms according to the Ar-40(n,gamma)Ar-41 nuclear reaction seems the most plausible.