Activation cross-sections for some 14·8 MeV neutron-induced nuclear reactions on caesium: Isomer ratios of 134Cs, 133Xe and 130I

Abstract

Absolute cross-sections for 14·8 MeV neutron-induced reactions on 133Cs were determined using the activation technique. The results, with maximum errors of 15 per cent, are: ρ(n,γ)=7·1 mb (ρ(n,γ) 134m Cs=1·82 mb, ρ(n,γ) 134g Cs=5·3 mb ; ρ(n,2n) 132 Cs=1620 mb ; ρ(n,p)=10·5 mb (ρ(n,p) 133m Xe=4·8 mb, ρ(n,p) 133g Xe=5·7 mb ; ρ(n,α)=1·14 mb (ρ(n,α) 130m I=0·54 mb, ρ(n,α) 130g I=0·6 mb ; ρ(n, 3 He) 131 I=3·2 μ barn ; ρ(n,2p) 132 I⩽12 μ barn . At this particle energy direct interaction processes also contribute. The isomer cross-section ratios σ m σ g for 134Cs, 133Xe and 130I are 0·34±0·08, 0·85±0·15 and 0·91±0·2 respectively. A reinvestigation of the alleged 127I ( n, 3 n) 125I reaction showed that the earlier measurement was in error.