Fei Tuo

Measurements of activation cross-sections for the 96Ru(n,d*)95gTc reaction for neutrons with energies between 13.3 and 15.0 MeV

In this study, activation cross-sections were measured for the (9)(6)Ru(n,d*)(95g)Tc reaction at three different neutron energies from 13.5 to 14.8MeV. The fast neutrons were produced via the (3)H(d,n)(4)He reaction on a K-400 neutron generator. Induced gamma activities were measured by a high-resolution gamma-ray spectrometer with a high-purity germanium (HPGe) detector. Measurements were corrected for gamma-ray attenuations, random coincidence (pile-up), dead time and fluctuation of neutron flux. The data for (9)(6)Ru(n,d*)(95g)Tc reaction cross-sections are reported to be 196+/-18, 253+/-22 and 298+/-22mb at 13.5+/-0.2, 14.1+/-0.1 and 14.8+/-0.2MeV incident neutron energies, respectively. Results were compared with the previous works.

Cross-section measurements for (n, 2n) and (n,p) reactions on tellurium isotopes in the neutron energy range of 13.5-14.6 MeV

Cross sections for (n,2n) and (n,p) reactions have been measured on tellurium isotopes at the neutron energies of 13.5−14.6 MeV using the activation technique. Data are reported for the following reactions: 120Te(n,2n)119mTe, 120Te(n,2n)119gTe, 122Te(n,2n)121mTe, 122Te(n,2n)121gTe, 124Te(n,2n)123mTe, 128Te(n,2n)127gTe, 130Te(n,2n)129mTe, 120Te(n,p)120mSb, 122Te(n,p)122m+gSb, 124Te(n,p)124m+gSb, 126Te(n,p)126m+gSb and 128Te(n,p)128m+gSb. These new data for the cross sections of tellurium isotopes have smaller uncertainties than those reported in the previous literature. The first data for the 120Te(n,p)120mSb reaction cross sections are presented. In our experiment, natural high-purity tellurium powder was used as target material and the samples were wrapped in cadmium foil during the irradiation so the influence of the (n,γ) reactions of thermal neutrons was reduced to a low level and the interfering reactions were avoided or subtracted. The HPGe detector employed in this work has better resolution than NaI(Tl). Furthermore, while gamma-ray yields were measured and then turned into cross sections using the formula in Sect. 2.2, the most recent and accurate nuclear data available were adopted. These cumulative improvements should make our results more accurate and reliable than those reported in the previous literature. Our results are useful for verifying the accuracy of nuclear models used in the calculation of cross sections and are expected to help new evaluations of the 14 MeV neutron cross sections on isotopes of tellurium.

Activation cross-sections for 158Dy(n,p)158Tb, 156Dy(n,α)153Gd and 160Dy(n,p)160Tb reactions induced by neutrons at 14.7 MeV

The cross-sections for the (158)Dy(n,p)(158)Tb, (156)Dy(n,alpha)(153)Gd and (160)Dy(n,p)(160)Tb reactions induced by 14.7MeV neutrons were measured in this work and calculated by a previously developed formula. Measurements were corrected for gamma-ray attenuations, random coincidence (pile-up), dead time and fluctuation of neutron flux. Nuclear model calculations using the code HFTT, which employs the Hauser-Feshbach (statistical model) and exciton model (precompound effects) formalisms, were undertaken to describe the formation of the products.

Cross-section measurements for (n, 2n) and (n, α) reactions on yttrium at neutron energies from 13.5 to 14.6MeV

The cross sections for the reactions (89)Y(n, 2n) (88m+g)Y and (89)Y(n, alpha) (86m+g)RB induced by 14MeV neutrons have been measured using the activation technique and a coaxial HPGe gamma-ray detector. Spectroscopically pure Y(2)O(3) powder was used. Fast neutrons were produced by the T(d, n) (4)He reaction. The neutron fluencies were determined using the monitor reaction (93)Nb(n, 2n) (92m)Nb.

Assessment of radioactivity level and associated radiation exposure in topsoil from eastern region of Shangrao Prefecture, China

Natural and fallout radioactivity were estimated in topsoil samples collected in eastern region of Shangrao Prefecture, China. The average activity concentrations of 238U, 226Ra, 232Th and 40K in the soil were nearly 2 times the world median value and Chinese average. The 137Cs activity concentration decreased compared with the previously reported value in the same region. The absorbed dose rate and annual effective dose rate estimated in the study area are found to be both higher than the world average values. 238U/226Ra and 232Th/226Ra activity ratios were also considered in this study.