Photon Production Cross Section for ¹⁸¹ Ta

The ¹⁸¹Ta(n,xγ) reaction has been measured for neutron energies E_n = 2 to 100 MeV and for gamma-ray energies E_γ = 2 to 25 MeV using an array of bismuth germanate detectors and the pulsed neutron source at the Los Alamos Meson Physics Facility. The integrated photon production cross section reaches a maximum at ∼ 7.5 MeV. Above 20 MeV, the cross section increases slowly with energy. The angular distributions of the photon production cross sections for different neutron energies are isotropic. At all measured neutron energies the gamma-ray spectra have the simple evaporation form.