A Determination of the High Altitude Latitude Dependence in Cosmic-Ray Neutron Intensity

Abstract

High altitude flights have been made with balloon-borne neutron-detecting equipment at 30.4\ifmmode^\circ\else\textdegree\fi{}N and 54.7\ifmmode^\circ\else\textdegree\fi{}N geomagnetic latitudes. A maximum neutron density was found at an absorption depth of 110 g/${\mathrm{cm}}^{2}$ at 30.4\ifmmode^\circ\else\textdegree\fi{}N and 100 g/${\mathrm{cm}}^{2}$ at 54.7\ifmmode^\circ\else\textdegree\fi{}N. The maximum neutron density at 54.7\ifmmode^\circ\else\textdegree\fi{}N is approximately 2.9 times as great as the maximum neutron density measured at 30.4\ifmmode^\circ\else\textdegree\fi{}N. The total integrated neutron density at 54.7\ifmmode^\circ\else\textdegree\fi{}N is approximately 2.4 times as large as that at 30.4\ifmmode^\circ\else\textdegree\fi{}N. These results indicate a greater latitude effect for neutron densities than for total ionization, but less than for primary particles, thus corroborating present theories of neutron formation.