Virtual Excitation and Multiple Scattering Correction Terms to the Neutron Index of Refraction for Hydrogen

K Schoen; W M Snow; H Kaiser; S A Werner

doi:10.6028/jres.110.035

Virtual Excitation and Multiple Scattering Correction Terms to the Neutron Index of Refraction for Hydrogen

J Res Natl Inst Stand Technol. 2005 Jun 1;110(3):259-62. doi: 10.6028/jres.110.035. Print 2005 May-Jun.

Authors

K Schoen¹, W M Snow², H Kaiser¹, S A Werner¹

Affiliations

¹ University of Missouri-Columbia, Columbia, MO 65211, USA.
² Indiana University/IUCF, Bloomington, IN 47408, USA.

Abstract

The neutron index of refraction is generally derived theoretically in the Fermi approximation. However, the Fermi approximation neglects the effects of the binding of the nuclei of a material as well as multiple scattering. Calculations by Nowak introduced correction terms to the neutron index of refraction that are quadratic in the scattering length and of order 10(-3) fm for hydrogen and deuterium. These correction terms produce a small shift in the final value for the coherent scattering length of H2 in a recent neutron interferometry experiment.

Keywords: Nowak correction; neutron interferometry; neutron optics; refractive index; scattering length.