Radioactivity aspects of fusion reactors

Measurement of cross-sections for 14MeV neutron interaction with 175Lu

The cross-sections for 14MeV neutron interaction with ¹⁷⁵Lu were precisely measured by the neutron activation and off-line gamma ray technique. The neutron fluence was monitored by the accompanying α-particle of the T(d,n)α reaction, and the neutron energies were determined by using the cross-section ratio method of ⁹⁰Zr(n,2n)⁸⁹Zr to ⁹³Nb(n,2n)^92mNb reactions. As a result, the cross-sections of ¹⁷⁵Lu(n,2n)^174mLu, ¹⁷⁵Lu(n,2n)^174gLu, ¹⁷⁵Lu(n,p)^175m+gYb and ¹⁷⁵Lu(n,α)¹⁷²Tm reactions have been deduced at E_n = 14.1 ± 0.3MeV, 14.5 ± 0.3MeV and 14.7 ± 0.3MeV, respectively. Meanwhile, the comparisons between this work and the date reported by other groups previously were also given. For the comparison, it was found that there were nonnegligible discrepancies among these experimental data, as well as for several databases. As a conclusion, present data seem to be more consistent with the database of ENDF/B-VII.1, but trend to be lower than those of JEFF-3.2 and FENDL-3.1b, except the ¹⁷⁵Lu(n,2n)^174m+gLu reaction which are all in agreement.

Measurement of fission cross section for 232Th(n,x)89Rb reaction induced by neutrons around 14 MeV

In order to investigate the fission process in more detail, and to compare with the measurement of cumulative fission yields, the fission cross section of the (232)Th(n,x)(89)Rb reaction induced by 14 MeV neutron was measured using the activation technique. In our measurement the neutron flux was determined using the monitor (27)Al(n,α)(24)Na reaction, and the neutron energies were measured by the method of cross-section ratios of (90)Zr(n,2n)(89)Zr to (93)Nb(n,2n)(92m)Nb reactions. The cross sections were deduced as 14.0±0.9 mb at E(n)=14.7±0.3 MeV and 13.2±1.0 mb at E(n)=14.1±0.3 MeV.