Operation Greenhouse: Scientific Director's Report. Annex 1.5. Neutron Measurements. Part 2. Spectrum and Air Attenuation Static Measurements. Section 2. Nuclear Explosions, 1951 (Sanitized Version).

摘要

A preliminary report on the photographic neutron experiment was written Feb. 1, 1951. Since neither the philosophy of the experiment nor the method of carrying it out underwent significant changes after January 1951, the preliminary report is reproduced here as the first three chapters of this report. Chapter 4 outlines the changes which were introduced as well as the expanded objectives which dictated the nature of the most important of these changes. The Greenhouse series of experiments involved four nuclear detonations. These may be briefly described as follows neutron spectra generated in various types of nuclear detonations with particular emphasis on the scheduled thermonuclear tests. All measurements are to be made in collimated geometry and at a number of distances from the various explosions, thus making possible observations of essentially the prompt neutrons only, as well as a determination of the mean free path of these neutrons in air as a function of their energy. Mean-free-path determinations are essential if it is to be possible to deduce the absolute number of neutrons, as a function of energy, emanating from a bomb. It is fortunate for calculatory purposes that considerable data are already available on the mean free path of neutrons in air over a reasonable region of the energy spectrum under consideration.