Measurement of ²³²Th(n,)²³³Th, ⁹⁸Mo(n,)⁹⁹Mo, ¹⁸⁶W(n,)¹⁸⁷W, ¹¹⁵In(n,)^116m1In, and ⁹²Mo(n,p)^92mNb Cross Sections in the Energy Range of 1.6 to 3.7 MeV

Neutron-induced reaction cross sections for the reaction ²³²Th(n, )²³³Th have been measured at neutron energies of 1.6 ± 0.03 MeV, 2.2 ± 0.03 MeV, 3.0 ± 0.03 MeV, and 3.7 ± 0.03 MeV. We have also measured cross sections for the reactions ⁹⁸Mo(n, )⁹⁹Mo, ¹⁸⁶W(n, )¹⁸⁷W, ¹¹⁵In(n, )^116m1In, and ⁹²Mo(n, p)^92mNb at a neutron energy of 3.2 ± 0.03 MeV. The ⁷Li(p, n)⁷Be reaction was used as the neutron source with the proton beam from the 14-MV Pelletron accelerator, Mumbai, and the standard off-line gamma counting method was followed for activation measurement. The present measurements supplement the existing data and provide new data in the neutron energy range where no results are available. While the cross-section values for the ⁹⁸Mo(n, )⁹⁹Mo and ¹⁸⁶W(n, )¹⁸⁷W reactions are reported for the first time, the data for ⁹²Mo(n, p)^92mNb exists with a large discrepancy between the two available data sets. For the ¹¹⁵In(n, )^116m1In reaction, our measurement at 3.2 MeV is an additional data point where there exists significant disagreement among the data measured by different groups. The measurements are performed relative to the ¹¹⁵In(n, n^′)^115mIn and ¹⁹⁷ Au(n, )¹⁹⁸ Au cross sections of International Reactor Dosimetry File 2002. Detailed theoretical calculations using the statistical model code EMPIRE-II (latest version EMPIRE-2.19) have been performed. Good agreement with the present data along with the existing data set has been obtained by suitable adjustment of the level density parameter for all the systems. The experimental and theoretical results have been compared with the recent evaluations of ENDF/B-VII.0, JENDL-4.0, and JEFF-3.1.