Measurement of thermal neutron radiative capture cross-sections of the 14N and 19F by in-beam γ-spectroscopy method with reactor neutrons

The cross-sections of the 14N(n,γ) 15N and 19F(n,γ) 20F reactions were measured by γ-spectroscopy method with the target placed at the end of a neutron guide of the WWR-M reactor (PNPI, Gatchina). The neutron spectrum was measured by the TOF method. The maximum of the spectrum is located at 0.028(2) eV and FWHM is about 0.03 eV. Cross-section of radiative neutron capture in aluminium and absolute γ-intensities of the 1779 and 1633 keV γ-lines from beta decay of the 28Al and 20F, respectively, and the prompt 1678 and 1885 keV γ-lines from the 14N(n,γ) 15N reaction were taken as standards. The thermal neutron radiative cross-sections of the 14N and 19F were measured to be 0.0795(13) and 0.00950(15)b, respectively. New value of the γ-intensity of the 1678 keV γ-line from the 14N(n,γ) 15N reaction has been proposed.