Hitoshi Sakane

Measurement of activation cross-sections for (n,2n) reactions producing short-lived nuclei in the energy range between 13.4 and 14.9 MeV

Abstract Activation cross-sections for 18 (n,2n) reactions producing short-lived nuclei with half-lives between 20 s and 38 min were measured in the energy range between 13.4 and 14.9 MeV by an activation method. The measured target isotopes were 14N, 31P, 54Fe, 63Cu, 79Br, 87Rb, 92Mo, 108Pd, 113In, 132Ba, 138Ba, 140Ce, 141Pr, 144Sm and 165Ho. Four cross-sections for 108Pd, 132Ba, 144Sm and 165Ho were obtained at six-point energies for the first time. The intense 14 MeV neutron source facility (OKTAVIAN) at Osaka University was used for irradiation. All cross-section values were relatively obtained on the basis of the standard cross-section of 27Al(n, α) 24Na reaction (ENDF/B-VI). To obtain reliable neutron activation cross-sections, careful attention was paid to neutron irradiation and induced activities measurement. The present results were compared with previous data and the evaluated data in JENDL-3.2, JENDL-Activation File and ENDF/B-VI. The previous data measured at multi-point energies show reasonable agreement with the present results in comparison with those at one-point energy. There are overestimations of the cross-section for 31P in JENDL-3.2 and ENDF/B-VI, and for 132Ba and 165Ho in JENDL-Activation File.

Measurement of activation cross-sections of (n, np+d) reactions producing short-lived nuclei in the energy range between 13.4 and 14.9 MeV using an intense neutron source OKTAVIAN

Abstract Activation cross-sections for 17 (n, np+d) reactions producing short-lived nuclei with half-lives between 42 s and 23 min, were measured in the energy range between 13.4 and 14.9 MeV by an activation method. The measured target isotopes were 26 Mg, 29, 30 Si, 53, 54 Cr, 67 Zn, 87 Sr, 98, 100 Mo, 102 Ru, 105, 106, 108 Pd, 123 Te, 163 Dy, 179 Hf and 189 Os. Eleven cross-sections for 26 Mg, 30 Si, 87 Sr, 100 Mo, 102 Ru, 105, 106 Pd, 123 Te, 163 Dy, 179 Hf and 189 Os were obtained for the first time, and four cross-sections for 53, 54 Cr, 67 Zn and 108 Pd were obtained at six-point energies for the first time. An intense 14 MeV neutron source, OKTAVIAN at Osaka University was used for irradiation. All cross-section values were relatively obtained on the basis of the standard cross-section of 27 Al(n, α) 24 Na reaction (ENDF/B-VI). To obtain reliable neutron activation cross-sections, careful attention was paid to neutron irradiation and induced activity measurement. The present results were compared with the evaluated data in JENDL-3.2, JENDL-Activation File and ENDF/B-VI. The cross-sections are underestimated for 102 Ru and 108 Pd in JENDL-3.2.

Precise Intensity Measurements in the 14N(n, γ)15N Reaction as a γ-Ray Intensity Standard up to 11MeV

The main γ-ray intensities in the 14N(n, γ)15N reaction were determined at an accuracy of 0.3–1.0% based on the intensity balance principle. Measurements were performed at the supermirror neutron guide tube at the Kyoto University reactor (KUR). A liquid nitrogen target and a deuterated melamine (C3D6N6) one were used. We prepared a full-energy-peak efficiency curve by combining the measured and calculated efficiency curves. The previous values widely used as intensity standards agreed with the present results within 4–5% in the 2–11 MeV region, but the ratio to the present values showed a monotonic decrease with the increase in _-ray energy. The results reported by Belgya in 2006 agreed with the present one within 2–3% in the 2–8MeV region; nevertheless, the ratio showed a small oscillation versusγ-ray energy.

Measurement of the activation cross-sections of (n,np+d) reactions for lanthanide isotopes in the energy range between 13.4 and 14.9 MeV

Abstract The activation cross-sections for nine ( n , np + d ) reactions were measured by the activation method in the energy range between 13.4 and 14.9 MeV. The irradiated targets were lanthanide isotopes: 146,148 Nd, 152 Sm, 155, 158 Gd, 164 Dy, 170 Er, and 174,176 Yb. The cross-sections, except for 170 Er, were obtained for the first time. The D–T neutron source of the fusion neutronics source (FNS) at the Japan Atomic Energy Research Institute was used for irradiation. All cross-section values were determined relative to that of the 27 Al( n , α ) 24 Na reaction (ENDF/B-VI). To obtain reliable activation cross-sections, careful attention was paid to the corrections of the neutrons irradiation and induced activity measurements, as well as the effective neutron energy determination at the irradiation positions. To measure weak activities, a highly efficient measuring technique with a well-type HPGe detector was applied. The present results were compared with the comprehensive evaluated data in the JENDL-3.2, JENDL-Activation File, ENDF/B-VI and FENDL/A-2.0. Most of the evaluated data were overestimated or underestimated by more than 30%. Especially, there were the large underestimations for 164 Dy, 170 Er, 174 Yb and 176 Yb in FENDL/A-2.0.

Measurements of the (n, np+d) activation cross sections with 13.4–14.9 MeV neutrons using a fusion neutronics source/JAERI

Abstract The activation cross sections for 20 ( n , np + d ) reactions were measured in the energy range between 13.4 and 14.9 MeV by the activation method. The mass-separated isotopes of 87 Sr, 95,100 Mo, 104 Ru, 106 Pd, 113,116 Cd, 118,119,120 Sn, 123,128,130 Te, 184,186 W, and 189,190 Os were irradiated. The 16 cross sections, excepting those for 118 Sn, 128 Te and 184,186 W, were obtained for the first time. The d–T neutron source of the fusion neutronics source (FNS) at the Japan Atomic Energy Research Institute (JAERI) was used for irradiation. All cross section values were determined relative to that of the 27 Al ( n , α ) 24 Na reaction (ENDF/B-VI). To measure weakly induced activities, an efficiency calibration technique with a well-type HPGe detector was applied. The present results were compared with the comprehensive evaluated data in the JENDL-3.3, the JENDL-Activation File, the ENDF/B-VI and the FENDL/A-2.0. Most of the data in the JENDL-3.3 and the JENDL-Activation File were in good agreement with the present result. However, relative to our values, 13 of the 20 evaluated data in FENDL/A-2.0 were overestimated more than 2 times or underestimated by less than one tenth.

Cross-section measurement for the 17O(n, p)17N reaction by 14-MeV neutrons

Abstract Cross sections for the 17O(n,p)17N (T1/2 = 4.7 s) reaction in the energy region between 13.7 and 14.9 were measured by the activation method using the Fusion Neutronics Source (FNS) at the Japan Atomic Energy Research Institute. Cross sections for the reaction obtained were 23 ± 5, 11 ± 4, and <7 mb at 14.9 ± 0.1, 14.4 ± 0.1, and 13.7 ± 0.1 MeV, respectively. This work uniquely gives the experimental partial excitation function for the ~14-MeV reaction.