A new paper on the experimental results of the neutron scattering cross sections of noble gases was published.

It was found that the total scattring cross section of He-4 is about 10% smaller than existing data.

"Measurement of the total neutron-scattering cross-section ratios of noble gases of natural isotopic composition using a pulsed neutron beam",

C.C. Hadock, M. Hiromoto, T. Shima et al., Physical Review C 100, 064002 (2019)

https://doi.org/10.1103/PhysRevC.100.064002