Experimental study on beryllium-7 production via sequential reactions in lithium-containing compounds irradiated by 14 MeV neutrons

摘要

Except for H-3 and C-14, no radioactive nuclide is produced by neutron-induced reactions with lithium in lithium-containing materials such as Li2O and Li2CO3. However, when the lithium-containing materials are irradiated by 14 MeV neutrons, radioactive Be-7 is produced by sequential charged particle reactions (SCPR). In this study, we measured effective Be-7 production cross-sections in several lithium-containing samples at 14 MeV: the cross-sections are in the order of mub. Estimation of the effective cross-sections is attempted, and the estimated values agreed well with the experimental data. It was shown that the Be-7 activity in a unit volume of lithium-containing materials in D-T fusion reactors can exceed total activity of the same unit volume of the SiC structural material in a certain cooling time. Consequently, a careful consideration of the Be-7 production by SCPR is required to assess radioactive inventories in lithium-containing D-T fusion blanket materials. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 12]