Terrestrial and solar neutrons

Abstract

The study of neutrons in the solar system is reviewed, and the theories and experiments that relate to this study are described. Neutron capture in the atmosphere produces among other isotopes carbon 14 and tritium. The earth's neutron albedo is also a source of Van Allen radiation. The importance of the source is, however, in doubt; therefore, some studies of geomagnetically trapped charged radiation are also reviewed to emphasize the areas of greatest uncertainty in the theory of injection by the neutron albedo. There are conflicting data on the absolute value of the albedo itself, although there is now better agreement on neutron fluxes within the atmosphere. Hence a critical review of the techniques employed in neutron experiments is undertaken, and some possible ways of resolving some of the difficulties are suggested. The search for solar neutrons is also described, and some possible solar‐neutron experiments are suggested. In the study of both Van Allen and solar problems, high‐energy neutrons are most interesting, and yet this energy region is the least explored.