Measurement of 232Th(n,γ)233Th, 98Mo(n,γ)99Mo, 186W(n,γ) 187W, 115In(n,γ)116ml In, 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 Th-232(n, y)Th-233 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 Mo-98(n, y)Mo-99, W-186(n, y) W-187, (115) In(n, y)(116ml) In, and Mo-92(n, p)Nb-92m at a neutron energy of 3.2 +/- 0.03 MeV. The (7) Li( p, n)(7) Be 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 Mo-98(n, y)Mo-99 and W-186(n, y)W-187 reactions are reported for the first time, the data for Mo-92(n, p)Nb-92m exists with a large discrepancy between the two available data sets. For the In-115(n, y)(116ml) In 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 (115) In(n,n')(115m) In and Au-197(n, y)Au-198 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.