Cross sections for fast-neutron interaction with Lu, Tb, and Ta isotopes

Abstract

The cross sections for (n,x) reactions with Lu, Tb, and Ta isotopes were measured at (d,t) neutron energies around 14 MeV with the activation technique using metal foils of natural composition. Additionally, tantalum samples were irradiated with (d,d) neutrons and filtered neutron beams. To ensure an acceptable precision of the results all major sources of uncertainties were taken into account. Calculations of efficiency and correction factors were performed with the Monte Carlo technique. The cross section results obtained for the 175 Lu(n,α) 172 Tm reaction at (d,t) neutron energies are reported for the first time. 181 Ta(n,γ ) 182 Ta m2 reaction cross sections were also measured for the first time at 1.9, 58.7, and 144.3 keV and at 2.85 MeV. The earlier evaluated cross section upper estimate for the nuclear reaction 159 Tb(n,n α) 155 Eu is reported in this article to be one order lower. Some other cross sections were obtained with higher precision. Theoretical calculations of excitation functions were performed with the TALYS-1.0 code and compared with the experimental cross section values.

New Direction in Nuclear Physics Originated from the Neutron Activation Technique Application

“…First and second reaction of listed above with cross sections 1,913 ± 60 mb (14.6 MeV) and 2.2 ± 0.3 mb (14.6 MeV) accordingly, were used as "the probing reactions" to make sure that all the steps of our neutron activation technique are implemented in a proper way. A very good correspondence of our cross-section results and the measurement results of other groups was used as a proof of correctness of our experimental technique [2].…”

“…For the other two reactions, the early available cross-section data were either uncertain or missing at all [2]. Therefore, our results contributed to filling in the corresponding gaps in nuclear data.…”

“…For the last ten years, we have studied neutroninduced nuclear reactions on rare earth elements with application of the neutron activation technique. Our elements of interest were Tb and Lu [2]. For the first of these two elements, the following reactions were thoroughly investigated: 159 Tb(n, 2n) 158m+g Tb; 159 Tb(n, α) 156 Eu; 159 Tb(n, p) 159 Gd;…”

Possible observation of the dineutron in the 159 Tb (n, 2 n) 158g Tb nuclear reaction

“…He suggested that while the dineutron is known to be unbound, in the field of the heavy nucleus it may exist as a bonded particle near (a) E-mail: IMKadenko@univ.kiev.ua the nuclear surface of this heavy nucleus. In this study our attention was focused on Terbium (Tb, A = 158-160, 158g Tb: T 1/2 = 180 y) as an element of the rare-earth group based on our previous research [5,6]. A reason to select Tb is its special nuclear properties, such as strong deformation in ground state.…”