Determination of the Coherent Neutron Scattering Amplitudes of Boron, Nitrogen, and Oxygen by Mirror Reflection

The coherent neutron scattering amplitudes of boron, nitrogen, and oxygen have been measured by the mirror-reflection method. The measured values are $a_{\mathrm{B}}=(5.40\mathrm{}\pm 0.04)\times {10}^{-13\mathrm{}}$ cm, $a_{\mathrm{N}}=(9.19\mathrm{}\pm 0.11)\times {10}^{-13\mathrm{}}$ cm, and $a_{\mathrm{O}}=(5.80\mathrm{}\pm 0.05)\times {10}^{-13\mathrm{}}$ cm. The nitrogen and oxygen values are in agreement with previous measurements. The boron measurement is discussed with regard to the amplitudes of the separate isotopes, and evidence for a resonance in the ${\mathrm{B}}^{10}$ scattering cross section is given.