Energy and Angular Distribution of Neutrons and Gamma Rays Operation HENRE

The HENRE experiment, conducted at the Nevada Test Site in the winter and summer of 1967, was an extension of the experimental programs related to the Ichiban program to determine the doses received by the survivors at Hiroshima and Nagasaki. This report presents the data obtained on the neutron and gamma-ray dose as a function of polar angle, the fast neutron spectrum as a function of distance, and the high energy gamma-ray spectrum as a function of polar angle. It was found that the neutron spectrum did not reach equilibrium within the distances at which measurements were made. This has an effect on the dose as a function of polar angle measured with different air densities. In addition, the measurements show the gamma-ray dose received from angles below the air-ground interface is affected by the diffuse source of gamma rays.