Density of Resonance Neutrons in Hydrogenous Media Near the Source

This report was written by D.V. Booker, E. Broda and L. Kowarski at the Cavendish Laboratory (Cambridge) in January 1944 and is about the density of resonance neutrons in hydrogenous media near the source. Neutron-absorbing properties of a medium sometimes cannot be studied by the usual density integration technique because the amount of medium, or the intensity far from the source is insufficient. In such cases many useful deductions can be made from single-point activation measurements in a medium of known behaviour provided the differences between the scattering properties of the two media are negligible, insofar as they influence the observed activations, or can be allowed for. The relevant properties of a hydrogenous medium are discussed in this report and the activation of resonance detectors in H₃BO₃ is compared to the activation in C₁₀H₈, used as a reference medium. (nowak)