Extraction of the neutron–electron scattering length from the neutron diffraction data measured on noble gases

A new method of extracting the neutron–electron scattering length bne, which is directly connected with the fundamental physical value of neutron mean squared charge radius, from the slow neutron diffraction on noble gases was developed and verified by the analysis of literature data on structure factors for gaseous Kr and 36Ar and for liquid Kr.Different variants of analysis of these experimental data allow us to obtain bne value with the statistical accuracy of 10–20%, but in some of them the real possibility for the accessible accuracy no worse than 2–3% was shown. In order to remove some systematical uncertainties and to reach such a good accuracy the execution of comparative diffraction measurements is proposed with a pair of gases having close atomic properties and different n,e-scattering contributions, such as Ar–36Ar or Xe–Kr.