THIN-LAYER ACTIVATION OF NONMETALLIC MATERIALS BY USING NUCLEAR IMPLANTATION

Nuclear implantation of the cyclotron produced Be-7 isotope was used f or labeling of plastic and other materials that cannot be activated in nuclear wear measurements [1]. In our experiments boron of natural co mposition was used in the form of a NiBSi metallic-glass foil as impla ntation target through the B-nat(p, x)Be-7 nuclear reactions [2]. Kapt on (C22H10O5N2) and beryllium targets are also suitable by using a He- 3 beam [through C-12(He-3, 2 alpha)Be-7 and Be-9(He-7, alpha n)Be-7 re actions, respectively] to produce a high flux of radioactive Be-7 in o rder to implant a very thin surface layer of the secondary target. The chosen secondary target should have a composition which does not cont ain elements which can be activated by the bombarding beam. This condi tion was controlled separately by the bombardment with the same beam. This control-irradiation is also useful to make corrections for possib le interferences. Based on our early and recent experiences we have ch osen Be as implantation target, having the most proper conditions for nuclear implantation.