Measurements of (n, 2n) Reaction Cross Sections at 14 MeV for Several Nuclei

Measurements of (n, 2n) reaction cross sections to produce ⁸⁴Rb, ⁸⁶Rb, ⁸⁸Y, ¹³⁹Ce, ¹⁴¹Ce, ¹⁶⁸Tm, ^174m+gLu, ^180mTa, ^184m+gRe, ^196n+gAu, and ²³⁷U were carried out in the range of 13.4 to 14.8 MeV. The samples were irradiated at various positions on the surface of a two-ring orientation instrument with a 20-cm radius centered at the deuterium-tritium neutron source. The ²⁷Al(n,)²⁴Na reaction was used to monitor the neutron fluence in the target samples. The neutron energies of different directions were determined using the ratio of ⁸⁹Zr to ^92mNb specific activities induced in Zr and Nb foils by (n, 2n) reactions. The (n, 2n) products were measured using a calibrated Ge detector. Experimental uncertainty was within ±4%. The results are presented and compared with the results of references and ENDF/B-VII.0 evaluations. Cross sections of ⁸⁵Rb(n, 2n)⁸⁴Rb, ¹⁴⁰Ce(n, 2n)¹³⁹Ce, and ⁸⁹Y(n, 2n)⁸⁸Y were in good agreement with those of ENDF/B-VII.0 evaluations; however, disagreements were observed for ¹⁷⁵Lu(n, 2n)¹⁷⁴Lu and ¹⁴²Ce(n, 2n)¹⁴¹Ce between the present data and the ENDF/B-VII.0 evaluation file. The present data showed improvement in accuracy in comparison with previously reported data; therefore, the results should be offered for evaluations of neutron (n, 2n) cross sections.